Write a code of grading system using Switch---case

#include<stdio.h>
int main()
{
int a,m;
scanf("%d", &a);
m=a<=100 && a>=80?1:a<80 && a>=75?2:a<75 && a>=70?3:a<70 && a>=65?4:a<65 && a>=60?5:a<60 && a>=55?6:a<55 && a>=50?7:a<50 && a>=45?8:a<45 && a>=40?9:10;
switch(m)
{
case 1: printf("A+");
break;
case 2: printf("A");
break;
case 3: printf("A-");
break;
case 4: printf("B+");
break;
case 5: printf("B");
break;
case 6: printf("B-");
break;
case 7: printf("C+");
break;
case 8: printf("C");
break;
case 9: printf("D");
break;
default: printf("Fail");
break;
}

return 0;
}

Functional C programming

• Write a function to calculate the factorial value of any integer entered through the keyboard.
  
  #include<stdio.h>
  #include<conio.h>
  long int factorial(int n); 
  void main()
  {       
  clrscr();
  long int n,res,x;
  scanf("%ld",&n);
  res=factorial(n);
  printf("%ld",res);
  getch();
  }
  long int factorial(int n)
  {
  int rem=1,i;
    for(i=n;i>=1;i--)
    rem=rem*i;
    return rem;
    }
• Write a  function power(a,b)  to  calculate the value  of  a raised to b .
  
  #include<stdio.h>
  #include<conio.h>
  int power(int a,int b);
  void main()
  {
  clrscr();
  int i,x,sum,r,n;
  
  scanf("%d%d",&x,&n);
  r=power(x,n);
  printf("%d",r);
  getch();
  }
  int power(int a,int b)
  {
  int i,res=1;
  for(i=b;i>=1;i--)
  res=a*res;
  return res;
  }
• Write a function to calculate LCM of two numbers.
  
  #include<stdio.h>
  #include<conio.h>
  int lcm(int a,int b);
  void main()
  {
  clrscr();
  int a,b,i,x,y,res;
  scanf("%d%d",&x,&y);
  res=lcm(x,y);
  printf("LCM is:\n%d",res);
  getch();
  }
  
  int lcm(int a,int b)
  {
  int i;
  for(i=1; ;i++)
  {
  if(i%a==0&&i%b==0)
  break;
  }
  return i;
  }
• Write a function to calculate GCD of two numbers.
  #include<stdio.h>
  #include<conio.h>
  int gcd(int a,int b);
  void main()
  {
  clrscr();
  int x,y,res;
  scanf("%d%d",&x,&y);
  
  res=gcd(x,y);
  printf("%d",res);
  
  getch();
  }
  int gcd(int a,int b)
  {
  int rem;
      while(b>0)
      {
      rem=a%b;
      a=b;
      b=rem;
        }
  return a;
  }
• Any year is entered through the keyboard.Write a function to determine whether the year is a leap year or not.
  #include<stdio.h>
  #include<conio.h>
  int year(int y);
  void main()
  {
  clrscr();
  int y,res;
  printf("Enter the value of year?\n");
  scanf("%d",&y);
  res=year(y) ;
  
  
  getch();
  }
  int year(int y)
  {
  
  if(y%400==0)
  return    printf("It is leap year");
  else if(y%100==0)
  return    printf("It is not leap year");
  else if(y%4==0)
  return    printf("It is leap year");
  
  else
  return    printf("It is not leap year");
  }
• A prime integer is entered through the keyboard.Write a function  to obtain the prime factors  of this number.
  
  #include<stdio.h>
  #include<conio.h>
  
  int prime (int x);
  void main()
  {
  clrscr();
  int num;
  printf("Enter The Number:");
  scanf("%d",&num);
  int p,i;
  p=num;
  for(i=2;i<=(num/2);i++)
  {  if(prime(i))
     while(p%i==0)
       { printf("%d ",i);
         p=p/i;
       }
  
  }
  getch();
  }
  
  int prime (int x)
  {  int i=2;
     while(i<=(x/2))
       { if(x%i==0)
         break;
         ++i;
       }
     if (i>(x/2))
     return 1;
     else
     return 0;
  }
• Write a function which receives 5 integers and returns the sum, average and standard deviation of these numbers. Call this function from main() and print the results in main().
  #include<stdio.h>
  #include<conio.h>
  #include<math.h>
  int sum(int p,int q,int r,int s,int t);
  float average(float o);
  float sd(float m,float n);
  
  void main()
  {
  clrscr();
  int a,b,c,d,e,x;
  float y,z;
  printf("Enter the value of a:");
  scanf("%d",&a);
  printf("Enter the value of b:");
  scanf("%d",&b);
  printf("Enter the value of c:");
  scanf("%d",&c);
  printf("Enter the value of d:");
  scanf("%d",&d);
  printf("Enter the value of e:");
  scanf("%d",&e);
  x=sum(a,b,c,d,e);
  printf("\nSUM=%d",x);
  y=average(x);
  printf("\nAVERAGE=%f",y);
  z=sd(x,y);
  printf("\nSTANDARD DEVIATION=%f",z);
  
  getch();
  }
  int sum(int p,int q,int r,int s,int t)
  {
      return p+q+r+s+t;
  }
  float average(float o)
  {
      return o/5;
  }
  float sd(float m,float n)
  {
      return (sqrt(m-n));
  }
• A 5 digit positive integer is entered through the keyboard write a function to calculate sum of digits of the digit number.
  Using recursion:
  #include<stdio.h>
  #include<conio.h>
  int digitsum(int n);
  
  void main()
  {
    clrscr();
    int x;
    printf("Enter The Number:");
    scanf("%d",&x);
    printf("The Sum Is:%d",digitsum(x));
    getch();
  }
  
  int digitsum(int n)
  
  {
    int rem,sum;
    if(n==0)
       return 0;
    rem=n%10;
    n=n/10;
    sum=rem+digitsum(n);
    return sum;
  }
  
  Without using recursion:
  #include<stdio.h>
  #include<conio.h>
  int digitsum(int n);
  
  void main()
  {
    clrscr();
    int x;
    printf("Enter The Number:");
    scanf("%d",&x);
    printf("The Sum Is:%d",digitsum(x));
    getch();
  }
  
  int digitsum(int n)
  
  {
    int rem,sum=0,i;
    for (i=1;i<=5;i++)
    { rem=n%10;
      n=n/10;
      sum=sum+rem; }
    return sum;
  }
• A positive integer is entered through the keyboard, write a program  to obtain the prime factors recursively.
  #include<stdio.h>
  #include<conio.h>
  primefct(int x);
  void main()
  {
  clrscr();
  int x;
  printf("Enter an integer:");
  scanf("%d",&x);
  printf("the prime factors are:");
  primefct(x);
  getch();
  }
  
  primefct(int n)
  {
  int i;
  for(i=2;i<=n;i++)
  {
   if(n%i==0)
      {
      printf("%d ",i);
      primefct(n/i);
      break;
      }
  }
  }
• Write a recursive function to obtain the first 25 numbers of a Fibonacci  sequence.In a Fibonacci sequences the sum of two successive terms given the third term. Following are the first few term of the Fibonacci sequence:
  1         1          2           3           5           8          13           21           34          55.........
  
  #include<stdio.h>
  #include<conio.h>
  
  long int fib(long int m);
  void main()
  {
  clrscr();
  long int i;
  for(i=1;i<=25;i++)
     printf("\n%ld\n",fib(i));
  getch();
  
  }
  long int fib(long int m)
  {
  if(m<=2)
     return 1;
  else
     return fib(m-1)+fib(m-2);
  
  }
  
  
  
  

Array C programming

• Write a program to search for an element from an array input from the user.
  
  #include<stdio.h>
  #include<conio.h>
  
  void main()
  {
  clrscr();
  int num[5]={2,4,6,8,10},i,a;
  printf("Enter an element:");
  scanf("%d",&a);
       for(i=0;i<5;i++)
  {
       if(num[i]==a)
       {
       printf("\nFound");
       break;
       }
  }
       if(i==5)
      printf("\nNot Found");
   getch();
   }
• Inserting an element into a position of an array.The element and the insertion point are inputs form the user.
  
  #include<stdio.h>
  #include<conio.h>
  
  void main()
  {
  clrscr();
  int a[6]={10,2,8,5,9},p,e,i,j;
  printf("Enter the inserting point?\n");
  scanf("%d",&p);
  printf("Enter the element?\n");
  scanf("%d",&e);
  
  for(i=5;i>=p;i--)
      {
      j=i-1;
      a[i]=a[j];
      }
  a[p]=e;
  
  printf("The array is:\n");
  for(i=0;i<6;i++)
      printf(" %d,",a[i]);
  
  getch();
  }
• Inserting a number /character into the proper position of a array which is sorted in ascending /descending order.
  Ascending
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int a[5]={1,2,3,4,5},i,j,temp;
  for(i=0;i<5;i++)
  
  printf("%d",a[i]);
  
  for(i=0;i<5-1;i++)
         for(j=i+1;j<5;j++)
  
             if(a[i]<a[j])
           {    temp=a[i];
          a[i]=a[j];
          a[j]=temp;
          }
           for(i=0;i<5;i++)
      printf("\n%d",a[i]);
  
  
      getch();
      }
  Descending
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int a[5]={1,2,3,4,5},i,j,temp;
  for(i=0;i<5;i++)
  
  printf("%d",a[i]);
  
  
         for(i=0;i<5-1;i++)
         for(j=i+1;j<5;j++)
  
             if(a[i]>a[j])
           {    temp=a[i];
          a[i]=a[j];
          a[j]=temp;
          }
  
  
    for(i=0;i<5;i++)
      printf("\n%d",a[i]);
  
  
      getch();
      }
  
• Deleting an element from an array.
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int a[7]={2,4,8,10,12,15},i,j;
  printf("Deleting 8 from this array\n\n");
  for(i=2;i<6;i++)
      {
      j=i+1;
      a[i]=a[j];
      }
  
  printf("The array is ");
  for(i=0;i<5;i++)
      printf("%d,",a[i]);
  getch();
  }
• Write a program to find out the maximum, minimum and mode of an array of numbers.
  
  Maximum & Minimum
  
  #include<stdio.h>
  #include<conio.h>
  
  void printarray(int ar[]);
  
  void main()
  {
  
  clrscr();
  
  int num[10]={23,33,6,4,54,28,24,6,34,2};
  
  int i,k,temp,a;
  
  printarray(num);
  
  a=10/2;
  a=(num[a]+num[a-1])/2;
  printf("\nMEDIAN of this array is %d\n",a);
  
  for(i=0;i<9;i++)
      for(k=i+1;k<10;k++)
      {
       if(num[i]<num[k])
          {
           temp=num[i];
           num[i]=num[k];
           num[k]=temp;
          }
  
      }
  
  printf("\nMaximum number is %d\n",num[0]);
  printf("\nMinimum number is %d",num[9]);
  
  getch();
  }
  
  void printarray(int ar[])
  {
  
   int i;
   for(i=0;i<10;i++)
      printf("%d ",ar[i]);
  
   printf("\n\n");
  
  }
  
  Mode
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int a[6]={2,2,3,5,5,6},i,j;
  printf("Mode of this array is\n");
  for(i=0;i<6;i++)
      for(j=i+1;j<6;j++)
      {
           if(a[i]==a[j])
             {
          printf(" %d,",a[i]);
  
             }
      }
  
  getch();
  }
• Find k-th maximum and k-th minimum from an array.
  
  #include<stdio.h>
  #include<conio.h>
  void printarray(int ar[]);
  void main()
  {
  
  clrscr();
  
  int num[10]={23,10,3,4,54,28,30,6,34,2};
  
  int i,k,n,l,temp;
  
  printarray(num);
  
  for(i=0;i<9;i++)
      for(k=i+1;k<10;k++)
      {
       if(num[i]<num[k])
          {
           temp=num[i];
           num[i]=num[k];
           num[k]=temp;
          }
  
      }
  printarray(num);
  
  printf("Enter the value of K?\n");
  scanf("%d",&n);
  l=n-1;
  printf("\n%dth Maximum number is %d\n",n,num[l]);
  
  printf("\n\n");
  
  for(i=0;i<9;i++)
      for(k=i+1;k<10;k++)
      {
       if(num[i]>num[k])
          {
           temp=num[i];
           num[i]=num[k];
           num[k]=temp;
          }
  
      }
  printarray(num);
  
  printf("\n%dth Minimum number is %d",n,num[l]);
  
  getch();
  }
  
  void printarray(int ar[])
  {
  
   int i;
   for(i=0;i<10;i++)
      printf("%d ",ar[i]);
  
   printf("\n\n");
  }
• Write  a program to delete duplicate elements from an array.
  
  #include<stdio.h>
  #include<conio.h>
  
  void main()
  {
  clrscr();
  int a[7]={2,4,6,6,8,8,10},j,i,k,l;
  
  printf("\nOriginal array is\n ");
  for(i=0;i<7;i++)
      printf(" %d,",a[i]);
  
  for(i=0;i<7;i++)
      for(j=i+1;j<7;j++)
      {
      if(a[i]==a[j])
          {
          a[i]=NULL;
          for(k=i;k<7;k++)
            {
            l=k+1;
            a[k]=a[l];
            }
          }
      }
  printf("\nAfter deleting duplicate element,the array is\n ");
  for(i=0;i<5;i++)
      printf(" %d,",a[i]);
  getch();
  }
• Write a program to find the common characters from two arrays.
  
  #include<stdio.h>
  #include<conio.h>
  #include<string.h>
  
  void main()
  {
  clrscr();
  char str1[10],str2[10];
  int i,len,j,len1;
  
  gets(str1);
  gets(str2);
  
  len=strlen(str1);
  len1=strlen(str2);
  
  for(i=0;i<len;i++)
      for(j=0;j<len1;j++)
      {
      if(str1[i]==str2[j])
         {
         printf("%c",str1[i]);
         break;
         }
      }
  getch();
  }
• Take a string as input and print characters in reverse order.Don't use any built in string function.
  
  #include<stdio.h> #include<conio.h>
  #include<string.h>
  
  
  void main()
  {
  clrscr();
  int i, k , len;
  
  char str[100];
  char strrv[100];
  
  
  gets(str);
  
  len=strlen(str);
  
  k=0;
  
  for(i=len-1;i>=0;i--)
      {
      strrv[k]=str[i];
      k++;
      }
  
  
  strrv[len]=NULL;
  
  printf("Original String :%s\n",str);
  printf("Rerverse string :%s\n",strrv);
  
  getch();
  
  }
• Write a program to merge two arrays removing the duplicate elements.
  
  
  #include<stdio.h>
  #include<conio.h>
  
  void main()
  {
  clrscr();
  int arr1[7]={2,4,8,9},arr2[4]={4,8,10,12},i,j,l,k,a;
  for(i=0;i<4;i++)
      for(j=0;j<4;j++)
      {
      if(arr1[i]==arr2[j])
         {
          arr2[j]=NULL;
          for(k=j;k<3;k++)
          {
          l=k+1;
          arr2[k]=arr2[l];
          }
          break;
         }
      }
  
  a=4;
  for(i=0;i<2;i++)
      {
      arr1[a]=arr2[i];
      a=a+1;
      }
  for(i=0;i<6;i++)
  printf(" %d,",arr1[i]);
  
  getch();
  }
• Take a string as input and check whether it is  a palindrome.
  
  #include<stdio.h>
  #include<conio.h>
  #include<string.h>
  
  void main()
  {
  clrscr();
  int i,k,len;
  
  char arr1[100];
  char arr2[100];
  
  gets(arr1);
  
  len=strlen(arr1);
  
  k=0;
  
  for(i=len-1;i>=0;i--)
      {
      arr2[k]=arr1[i];
      k++;
      }
  
  arr2[len]=NULL;
  
  if(!strcmp(arr1,arr2))
      printf("\n PALINDROME");
  else
      printf("\n NOT PALINDROME");
  
  
  getch();
  
  }
• Write  a program to merge two sorted arrays.
  
  
  #include<stdio.h>
  #include<conio.h>
  void printary(int arr[]);
  void main()
  {
  clrscr();
  int a[5]={2,5,1,7,9},b[5]={3,6,8,4,10},i,num,c,j;
  
  printary(a);
  
  printary(b);
  c=5;
   for(i=0;i<5;i++)
  
      {
         a[c]=b[i];
         c=c+1;
      }
    printf("After merge the main array is:");
   for(i=0;i<10;i++)
  
    printf(" %d",a[i]);
      getch();
    }
  void printary(int arr[])
  {
  int j,i,a,temp;
  for(i=0;i<5;i++)
       for(i=0;i<5-1;i++)
         for(j=i+1;j<5;j++)
  
             if(arr[i]>arr[j])
           {    temp=arr[i];
          arr[i]=arr[j];
          arr[j]=temp;
          }
  for(i=0;i<5;i++)
      printf(" %d",arr[i]);
  
      print f("\n\n");
  }
• Write a program to count the frequencies of each character present in a text.
  
  #include<stdio.h>
  #include<conio.h>
  #include<string.h>
  void sort(char a[]);
  
  int len,k;
  void main()
  {
  clrscr();
  char a[100];
  int i,j,count=0,count1=0,count2=0;
  
  gets(a);
  
  printf("\n");
  len=strlen(a);
  for(i=0;i<len;i++)
      if(a[i]==' ')
      {
      count++;
      k=i;
      sort(a);
      i=i-1;
      }
  if(count>0)
      printf("space= %d\n\n",count);
  
  count=0;
  for(i=0;i<len;i++)
      if(a[i]=='.')
      {
      count++;
      k=i;
      sort(a);
      i=i-1;
      }
  
  if(count>0)
      printf(".= %d\n\n",count);
  
  for(i=0;i<len;i++)
      if(a[i]=='    ')
      {
      count2++;
      k=i;
      sort(a);
      i=i-1;
      }
  
  if(count2>0)
      printf("tab= %d\n\n",count2);
  
  
  for(i=0;i<len;i++)
      if(a[i]==',')
          {
          count1++;
          k=i;
          sort(a);
          i=i-1;
          }
  
  if(count1>0)
      printf(",= %d\n\n",count1);
  
  for(i=0;i<len;i++)
  {
  count=1;
      for(j=i+1;j<len;j++)
       if(a[i]==a[j])
       {
       count++;
       k=j;
       sort(a);
       len=strlen(a);
       j=j-1;
       }
  
  if(count>1)
  printf("%c= %d\n",a[i],count);
  
  }
  
  getch();
  }
  void sort(char a[])
  {
  int i,j;
  for(i=k;i<len;i++)
      {
      j=i+1;
      a[i]=a[j];
      }
  len=strlen(a);
  }
• Write a program to count the number of letters and words within a text.
  
  #include<stdio.h>
  #include<conio.h>
  #include<string.h>
  
  void main()
  {
  clrscr();
  char str[100];
  int i,len,count=0,s;
  gets(str);
  len=strlen(str);
  for(i=len-1;i>=0;i--)
      if(str[i]==' ')
      count++;
  s=count+1;
  printf("The number of words is:%d",s);
  printf("\nThe number of letters is:%d",len-count);
  getch();
  }
• Write a program which will search for a substring withing a string.
  
  #include<stdio.h>
  #include<conio.h>
  #include<string.h>
  void main()
  {
  clrscr();
  char str[100],substr[100];
  int i,k,len,len1,count=0;
  gets(str);
  printf("\n");
  gets(substr);
     len=strlen(str);
     len1=strlen(substr);
  for(i=0;i<len;i++)
   for(k=0;k<len1;k++)
   {
    if(str[i]==substr[k])
    count++;
    }
  printf("\n");
  if(count==len1)
      printf("Found");
  else
      printf("Not Found");
  
  getch();
  }
• Take a  n numbers as input from the user .Find out their GCD and LCM.
  GCD
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int a[100],i,rem,n,k,j;
  printf("How many number of GCD:");
  scanf("%d",&n);
  printf("Print %d numbers:\n",n);
  for(k=0;k<n;k++)
  scanf("%d",&a[k]);
  {
  for(i=0;i<n;i++)
  
  
     while(a[i+1]>0)
      {
       rem=a[0]%a[i+1];
       a[0]=a[i+1];
       a[i+1]=rem;
       }
  
  
    }
    printf("The GCD is:%d",a[0]);
  getch();
  }
  LCM
  #include<stdio.h>
  #include<conio.h>
  
  void main()
  {
  clrscr();
  int arr[100],a,b,n,i,rem;
  printf("How many number of LCM:");
  scanf("%d",&n);
  printf("Enter %d numbers:\n",n);
  for(i=0;i<n;i++)
      scanf("%d",&arr[i]);
  for(i=0;i<n-1;i++)
  {
      a=arr[i];
      b=arr[i+1];
      while(b>0)
      {
      rem=a%b;
      a=b;
      b=rem;
      }
      arr[i+1]=a*arr[i]/a*arr[i+1]/a;
  }
  printf("The LCM is :");
  printf("%d",arr[n-1]);
  getch();
  }
• Write a program to Add/Subtract two different matrices, input from the user.
  
  ADD
  
  #include<stdio.h>
  #include<conio.h>
  void mat(int arr[3][3]);
  void main()
  {
  clrscr();
  int m1[3][3],m2[3][3],m3[3][3],i,j;
  printf("Enter Matrix A:\n");
  mat(m1);
  printf("Enter Matrix B:\n");
  mat(m2);
  {
  for(i=0;i<3;i++)
  {
      for(j=0;j<3;j++)
  
  m3[i][j]=m1[i][j]+m2[i][j];
  }
   }
   printf("After adding two matrix(A+B):\n\n");
  
  for(i=0;i<3;i++)
  {
      for(j=0;j<3;j++)
  
       printf("  %d",m3[i][j]);
       printf(" \n");
   }
    getch();
    }
    void mat(int arr[3][3])
  {
  int r,c,a;
    for(r=0;r<3;r++)
  {
        for(c=0;c<3;c++)
        scanf("%d",&arr[r][c]);
   }
  for(r=0;r<3;r++)
  {
        for(c=0;c<3;c++)
        printf("  %d",arr[r][c]);
        printf("\n\n");
    }
  }
  
  Subtract
  #include<stdio.h>
  #include<conio.h>
  void mat(int arr[3][3]);
  void main()
  {
  clrscr();
  int m1[3][3],m2[3][3],m3[3][3],i,j;
  printf("Enter Matrix A:\n");
  mat(m1);
  printf("Enter Matrix B:\n");
  mat(m2);
  {
  for(i=0;i<3;i++)
  {
      for(j=0;j<3;j++)
  
  m3[i][j]=m1[i][j]-m2[i][j];
  }
   }
   printf("After subtracting two matrix(A-B):\n\n");
  
  for(i=0;i<3;i++)
  {
      for(j=0;j<3;j++)
  
       printf("  %d",m3[i][j]);
       printf(" \n");
   }
    getch();
    }
    void mat(int arr[3][3])
  {
  int r,c,a;
    for(r=0;r<3;r++)
  {
        for(c=0;c<3;c++)
        scanf("%d",&arr[r][c]);
   }
  for(r=0;r<3;r++)
  {
        for(c=0;c<3;c++)
        printf("  %d",arr[r][c]);
        printf("\n\n");
    }
  }
• Write a program to Multiply two matrices.
  
  #include<stdio.h>
  #include<conio.h>
  void mat(int arr[3][3]);
  void main()
  {
  clrscr();
  int m1[3][3],m2[3][3],m3[3][3],i,j,n,p;
  printf("Enter Matrix A:\n");
  mat(m1);
  printf("Enter Matrix B:\n");
  mat(m2);
   printf("After multiplying two matrix(A*B):\n\n");
  
  for(i=0;i<3;i++)
     {
      for(j=0;j<3;j++)
      {
      n=0;
      for(p=0;p<3;p++)
      n=n+m1[i][p]*m2[p][j];
      m3[i][j]=n;
  
        printf("  %d",m3[i][j]);
       }
       printf(" \n");
   }
    getch();
    }
    void mat(int arr[3][3])
  {
  int r,c,a;
    for(r=0;r<3;r++)
  {
        for(c=0;c<3;c++)
        scanf("%d",&arr[r][c]);
   }
  for(r=0;r<3;r++)
  {
        for(c=0;c<3;c++)
        printf("  %d",arr[r][c]);
        printf("\n\n");
    }
  }
• Write a program to find out the Transpose of a Matrix.
  
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int m[3][3],i,j;
  for(i=0;i<3;i++)
  {
  for(j=0;j<3;j++)
    scanf("%d",&m[i][j]);
  }
  
  printf("The original matrix is:\n");
  
  for(i=0;i<3;i++)
  {
  for(j=0;j<3;j++)
    printf("  %d",m[i][j]);
    printf(" \n\n");
  }
  printf("After transpose, the matrix is:\n");
  
  for(i=0;i<3;i++)
  {
  for(j=0;j<3;j++)
    printf("  %d",m[j][i]);
    printf(" \n\n");
  }
  
  
  getch();
  }
• Write a program to construct a  nxn magic square.
  
  
  #include<stdio.h>
  #include<conio.h>
  int matrix[100][100];
  void main()
  {
  clrscr();
  int r,c,start,num,n;
  printf("Please Enter the number of order:");
  scanf("%d",&n);
  start=n/2;
  num=2;
  matrix[0][start]=1;
  r=0;
  c=start;
  while(1)
  {
  r=r-1;
  c=c+1;
  if(r<0&&c<n)
  {
  r=n-1;
  matrix[r][c]=num;
  }
  else if(r>=0&&r<n&&c<n&&matrix[r][c]==0)
  {
  matrix[r][c]=num;
  }
  else if(r>=0&&r<n&&c>=n)
  {
  c=0;
  matrix[r][c]=num;
  }
  else if(r<0&&c>=n)
  {
  r=r+2;
  c=c-1;
  matrix[r][c]=num;
  }
  else if(r>=0&&r<n&&c>=0&&c<n&&matrix[r][c]!=0)
  {
  r=r+2;
  c=c-1;
  matrix[r][c]=num;
  }
  if(n*n==num)
  break;
  num++;
  }
  for(r=0;r<n;++r)
  {
  for(c=0;c<n;++c)
  {
  printf("%d  ",matrix[r][c]);
  }
  printf("\n\n");
  }
  getch();
  }
  
  
  
  

Looping C programming

• x and n are input through keyboard.Write a program to compute xn, n!, nCr, nPr
  
  xn
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int x,n,res=1;
  int i;
  printf("Enter the value of x?\n");
  scanf("%d",&x);
  printf("Enter the value of n?\n");
  scanf("%d",&n);
  for(i=0;i<n;i++)
  
  res=res*x;
  printf("Answer:%d",res);
  
  getch();
  }
  
  n!
  #include<stdio.h>
  #include<conio.h>
  
  void main()
  {
  int n,i,
  res=1;
  clrscr();
  printf("Enter the n=");
  scanf("%d",&n);
  for(i=n;i>=1;i--)
     res=res*i;
  printf("n!=%d",res);
  getch();
  }nCr
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  long int n,r,sum=1,i,k,p,res=1,x,rem=1,f,ncr;
  printf("Enter the value of n:");
  scanf("%ld",&n);
  printf("Enter the value of r:");
  scanf("%ld",&r);
  p=n-r;
  for(i=n;i>=1;i--)
  {
  sum=sum*i;
  }
  for(k=p;k>=1;k--)
  {
  res=res*k;
  }
  for(x=r;x>=1;x--)
  {
  rem=rem*x;
  }
  f=res*rem;
  ncr=sum/f;
  printf("\nncr=%ld",ncr);
  getch();
  }
  nPr#include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  long int n,r,sum=1,i,k,p,res=1,l;
  printf("Enter the value of n:");
  scanf("%ld",&n);
  printf("Enter the value of r:");
  scanf("%ld",&r);
  p=n-r;
  for(i=n;i>=1;i--)
  
  sum=sum*i;
  
  
  for(k=p;k>=1;k--)
  {
  res=res*k;
  }
  l=sum/res;
  printf("\nnpr=%ld",l);
  getch();
  }
• Write a program to determine the GCD and LCM of 3 numbers.
  GCD#include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int a,b,c,rem;
  printf("Enter the value of a?\n");
  scanf("%d",&a);
  printf("Enter the value of b?\n");
  scanf("%d",&b);
  printf("Enter the value of c?\n");
  scanf("%d",&c);
  while(b>0)
      {
      rem=a%b;
      a=b;
      b=rem;
      }
  while(c>0)
      {
      rem=a%c;
      a=c;
      c=rem;
      }
  printf("GCD is:%d",a);
  getch();
  }
  LCM
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int a,b,c,i;
  printf("Enter the value of a?\n");
  scanf("%d",&a);
  printf("Enter the value of b?\n");
  scanf("%d",&b);
  printf("Enter the value of c?\n");
  scanf("%d",&c);
  for(i=1; ;i++)
  {
  if(i%a==0&&i%b==0&&i%c==0)
  break;
  }
  printf("LCM is:\n%d",i);
  getch();
  }
• Find out the sum of each of the following series. n is the input from user for series (4)
  1. 3+11+19+.........+1691.
  2. 7+20+33+.........(up to 100th term)
  3. 5-11+17-..........(up to 75th term)
  4. 2*7*12*...........*37
     
     
     
     
     
     
     
   1.
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  long int x=3,sum=0;
  for(x=3;x<=1691;x=x+8)
  {
  sum=sum+x;
  
  }
  printf("\n\nSUM:%ld",sum);
  getch();
  }
  2.
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  long int x=7,sum=0,i;
  for(i=1;i<=100;i++)
  {
  sum=sum+x;
  x=x+13;
  }
  printf("\n\nSUM:%ld",sum);
  getch();
  }
  3.
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  long int x=5,sum=0,i;
  for(i=1;i<=75;i++)
  {
  sum=sum+x;
  if(x>0)
      x=(x+6)*-1;
  else
      x=(x-6)*-1;
  }
  printf("\n\nSUM:%ld",sum);
  getch();
  }.
  4.
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  long int x=2,sum=1;
  for(x=2;x<=37;x=x+5)
  {
  sum=sum*x;
  
  }
  printf("\n\nSUM:%ld",sum);
  getch();
  }
• Write  a program to determine all prime numbers within the range [a.......b]
  where a & b are input through keyboard.
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int num,num1,i,n,l;
  scanf("%d",&num);
  scanf("%d",&num1);
  n=2;
  l=num;
  for(i=l;i<=num1;i++)
  {
  while(n<=i/2)
      {
      if(i%n==0)
          break;
      ++n;
      }
       if(n>i/2 && i!=2)
          printf(" %d",i);
      n=2;
      }
      getch();
      }
• Construct the following table.Here n is input from the user.
                       1             2              3          .....    n
                       2             4              6         .......   2n
                       3             6              9         .......   3n
                        .             .               .           .....     .
                        .             .               .          .......    .
                        .             .               .           .......   .
                        n           2n            3n          .......  nn
  
  #include<stdio.h>
  #include<conio.h>
  
  void main()
      {
      clrscr();
  
      int i,n,k;
      scanf("%d",&n);
  
      for(i=1;i<=n;i++)
      {
           for(k=1;k<=n;k++)
  
          printf("\t%d",k*i);
  
  
              printf("\n");
      }
        getch();
      }
• Write a program to find out first n perfect number where n is the input from user.
  
  #include<stdio.h>
  #include<conio.h>
  
  void main()
  {
  clrscr();
  int i,num,sum=0;
  printf("Enter a num");
  scanf("%d",&num);
  for(i=1;i<=num/2;i++)
     if(num%i==0)
     sum=sum+i;
     if(sum==num)
     printf("The number is a perfect number");
     else
      printf("The number is not a perfect number");
     getch();
    }
• Write a program to find first n Fibonacci number where n is the input from user.
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int n,a,b,sum,i,rem;
  a=0;
  b=1;
  printf("Enter the value of n?\n");
  scanf("%d",&n);
  printf("The fibonacci numbers are:");
  for(i=1;i<=n;i++)
      {
      sum=a+b;
      rem=sum;
      a=b;
      b=rem;
      printf("\n%d\n",sum);
      }
  getch();
  }
• Write a program to show the following triangle/rectangle of  "*" or numbers.Take n as inpute from user to determine the number of rows of the structure.(eg. n=5)
  1.
  #include<stdio.h>
  #include<conio.h>
  void main()                                                                                   {                                                                                        clrscr();                                                                          
                                                                                 
      int i,k,n;                                                             
      scanf("%d",&n);                                                       
  
  
  
      int c=1;                                                                   
      int s=n-1;                                                          
  
      for(i=1;i<=n;i++)
      {
  
         
          for(k=1;k<=s;k++)
          printf(" ");
          s--;
  
          for(k=1;k<=c;k++)
          printf("*");
  
          c=c+2;
          printf("\n");
      }
  
      getch();
      }
  
  2.
  #include<stdio.h>
  #include<conio.h>
  
  void main()
      {
      clrscr();
  
      int i,k,n;
      scanf("%d",&n);
      int c=1;
      int s=n-1;
                                                                                            
      for(i=1;i<=n;i++)                                                  
      {                                                                      
          for(k=1;k<=s;k++)                                      
          printf(" ");
          s--;                                                               
  
          for(k=1;k<=c;k++)
  
         if(k==1||k==c)
             printf("*");
         else if(i==n)
             printf("*");
          else
          printf(" ");
  
          c=c+2;
  
          printf("\n");
        }
      getch();
      }
  4.
  #include<stdio.h>
  #include<conio.h>
  
  void main()
      {
      clrscr();                                                                   
                                                                              
      int i,k,n;                                                            
      scanf("%d",&n);                                             
                                                                               
  
  
      int c=1;                                                            
      int s=n-1;  
  
      for(i=1;i<=n;i++)
      {
          for(k=1;k<=s;k++)                                        
          printf("*");
  
  
          for(k=1;k<=c;k++)
          printf("*");
  
          c=c;
              printf("\n");
      }
  
      getch();
      }
  5.
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int i,n,k;
  scanf("%d",&n);
  for(i=1;i<=n;i++)                                                            
  {
   for(k=1;k<=n;k++)
  { if(k==1||k==n)
      printf("*");
   else if(i==1||i==n)
      printf("*");
   else
      printf(" ");
         }
      printf("\n");
   }
  
  getch();
  }
  
  7.
  #include<stdio.h>
  #include<conio.h>
  
  void main()
      {
      clrscr();
  
      int i,k,n;
      scanf("%d",&n);
      int c=1;                                                                                                                      
      int s=n-1;
  
      for(i=1;i<=n;i++)
      {
  
          for(k=1;k<=s;k++)
          printf(" ");
          s--;
  
          for(k=1;k<=c;k++)
          printf("*");
  
          c=c+2;
          printf("\n");
      }
      c=c-4;
      s=1;
      for(i=1;i<=n;i++)
      {
  
          for(k=1;k<=s;k++)
          printf(" ");
          s++;
  
          for(k=1;k<=c;k++)
          printf("*");
  
          c=c-2;
          printf("\n");
      }
  
      getch();
      }
  
  8.
  #include<stdio.h>
  #include<conio.h>
  
  void main()
      {
      clrscr();
  
      int i,k,n;
      scanf("%d",&n);
      int c=1;
      int s=n-1;                                                                          
       for(i=1;i<=n;i++)                                                                                   
      { 
          for(k=1;k<=s;k++)
          printf(" ");
          s--;
  
          for(k=1;k<=c;k++)
          printf("*");
  
          c=c+2;
          printf("\n");
      }
      c=c-4;
      s=1;
      for(i=1;i<=n;i++)
      {
  
          for(k=1;k<=s;k++)
          printf(" ");
          s++;
  
          for(k=1;k<=c;k++)
          printf("*");
  
          c=c-2;
          printf("\n");
      }
    getch();
      }
  
  10.
  #include<stdio.h>
  #include<conio.h>
  void main()
      {
      clrscr();
  
      int i,k,n;
      scanf("%d",&n);
  
  
  
      int c=(2*n)-1;
      int s=0;
  
  
      for(i=1;i<=n;i++)
      {
                                                                                           
       for(k=1;k<=s;k++)
          printf(" ");
          s++;
  
          for(k=1;k<=c;k++)
          printf("*");
  
          c=c-2;
          printf("\n");
      }
      c=3;
      s=n-2;
      n=n-1;
      for(i=1;i<=n;i++)
      {
  
          for(k=1;k<=s;k++)
          printf(" ");
          s--;
  
          for(k=1;k<=c;k++)
          printf("*");
  
          c=c+2;
          printf("\n");
      }
  
      getch();
      }
• Write a program to print out all Armstrong numbers between 1 and 10000.
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int num,sum=0,k,rem,i;
  for(i=1;i<=10000;i++)
  {
   num=i;
   sum=0;
  
        for(k=1;k<=i;k++)
      {
        rem=num%10;
        sum=sum+(rem*rem*rem);
        num=num/10;
      }
  
       if(sum==i)
       printf("\n%d\n",i);
       }
       getch();
    }
• Write a program to calculate how many 5 digit numbers can be created if the following terms apply:
  
  1. the leftmost digit is even
  2. the second digit is odd
  3. the third digit is a non even prime
  4. the fourth and fifth are two random digits not used before in the number.
     
     
     
     
     #include<stdio.h>
     #include<conio.h>
     
     long int prime(long int n);
     
     void main()
     {
     clrscr();
     long int a,b,c,d,e,i,rem,num,count=0;
     for(i=20000;i<=99999;i++)
     {
         rem=i%10;
         e=rem;
         num=i/10;
         rem=num%10;
         d=rem;
         num=num/10;
         rem=num%10;
         c=rem;
         num=num/10;
         rem=num%10;
         b=rem;
         num=num/10;
         a=num;
         if(a%2==0&&b%2!=0&&prime(c)&&d!=a&&d!=b&&d!=c&&e!=d&&e!=a&&e!=b&&e!=c)
                count++;
     
         }
     printf(" \nRESULT=%ld",count);
     getch();
     }
     
     long int prime (long int n)
     {       int m;
         m=2;
         while(m<=n/2)
         {
         if(n%m==0)
             break;
         ++m;
         }
         if(m>n/2&&n!=2&&n!=1&&n!=0)
             return 1;
         else
             return 0;
     }
     

Conditional C programming

• Three numbers are input through keyboard.Write a program to find out the maximum and minimum of those 3 numbers.
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int a,b,c;
  printf("Enter value of a?\n");
  scanf("%d",&a);
  printf("Enter value of b?\n");
  scanf("%d",&b);
  printf("Enter value of c?\n");
  scanf("%d",&c);
  
  if(a>b&&a>c)
      printf("\n Max a");
  if(b>a&&b>c)
      printf("\n Max b");
  if(c>a&&c>b)
      printf("\n Max c");
  if(a<b&&a<c)
      printf("\n\n Min a");
  if(b<a&&b<c)
      printf("\n\n Min b");
  if(c<a&&c<b)
      printf("\n\n Min c");
  getch();
  }

• Take  a year as input and determine whether  it is leap year.
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int year;
  printf("Enter a year to check for a leap year:");
  
  scanf("%d",&year);
  
  if((year%4==0 && year%100!=0)||(year%400==0))
  
       {
       printf("The entered year is a leap year.");
        }
  else
      {
       printf("The entered year is not a leap year.");
       }
  getch();
       }
• If  cost price and selling price of an  item is input  through the  keyboard, write a program to determine  whether the seller has made profit  or incurred loss.Also determine  how much profit  he made or loss he incurred.
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int x,y,sum;
  printf("Enter cost price x?\n");
  scanf("%d",&x);
  printf("Enter selling price y?\n");
  scanf("%d",&y);
  
  if(x<y)
      {
      printf("The seller has made profit");
      sum=y-x;
      printf("\nThe profit is:%d",sum);
      }
  else
      {
      printf("The seller has incurred loss");
      sum=x-y;
      printf("\nThe loss is:%d",sum);
      }
  getch();
  }
• Any  integer  is  input  through  keyboard. Write a program to find out  whether it is an odd number  or  even number.
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int num;
  printf("Enter a num:");
  scanf("%d",&num);
  
  if(num%2==0)
       printf("The occured number is even.");
  else
       printf("The occured number is odd.");
  getch();
  }
• A  5 digit number is entered through the keyboard. Write a program to obtain the reverse number and  to determine whether  the  original  numbers are  equal  or  not.
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  long int num,num1,rem,numb=0;
  
  printf("Enter the 5 digit number ?\n");
  scanf("%ld",&num);
  rem=num%10;
  numb=numb+(10000*rem);
  num1=num/10;
  rem=num1%10;
  numb=numb+(1000*rem);
  num1=num1/10;
  rem=num1%10;
  numb=numb+(100*rem);
  num1=num1/10;
  rem=num1%10;
  numb=numb+(10*rem);
  num1=num1/10;
  numb=numb+num1;
  printf("\nThe reverse number of this number is:%ld",numb);
  numb;
  if(numb==num)
      printf("\n\nThe numbers are equal");
  else
      printf("\n\nThe numbers are not equal");
  getch();
  }
• Aust  grading  policy  is:
  1. 80%  marks or above  is A+
  2. 75% to 79% marks is A
  3. 70% to 74% marks is A-
  4. 65% to 69% marks is B+
  5. 60% to 64% marks is B
  6. 55% to 59% marks is B-
  7. 50% to 54% marks is C+
  8. 45% to 49% marks is C
  9. 40% to 44% marks is D
  10. Below 40% is F
      
      Write  aprogram which will take an input from user and calculate the grade of a student according to Aust  grading policy based on that input. 
      #include<stdio.h>
      #include<conio.h>
      void main()
      {
      clrscr();
      int x;
      printf("Enter a mark:");
      scanf("%d",&x);
      if(x>=80)
      printf("The grade is:A+");
      else if(x>=75&&x<=79)
      printf("The grade is:A");
      else if(x>=70&&x<=74)
      printf("The grade is:A-");
      else if(x>=65&&x<=69)
      printf("The grade is:B+");
      else if(x>=60&&x<=64)
      printf("The grade is:B");
      else if(x>=55&&x<=59)
      printf("The grade is:B-");
      else if(x>=50&&x<=54)
      printf("The grade is:c+");
      else if(x>=45&&x<=49)
      printf("The grade is:c");
      else if(x>=40&&x<=44)
      printf("The grade is:c");
      else if(x<40)
      printf("The grade is:F");
      getch();
      }
      • A certain grade of steel is graded according to the following conditions:
        
        1.Hardness must be greater than 60
        2.Certain content must be less than 0.7
        3.Tensile strength must be greater than 5000
        
        
        The grades are as follow:
        
        
        Grade is 10 if all three conditions are met
        Grade is 9 if condition 1 and 2 are met
        Grade is 8 if condition 2 and 3 are met
        Grade is 7 if condition 1 and 3 are met
        Grade is 6 if only one condition is met
        Grade is 5 if one of the conditions are met
         Write a program which will require the user   give values of hardness, carbon content and tensile  strength  of  the steel   under consideration and output   the  grade  of the steel.
        
        
        #include<stdio.h>
        #include<conio.h>
        void main()
        {
        clrscr();
        
        int x,z;
        float y;
        printf("Enter the value of hardness?\n");
        scanf("%d",&x);
        printf("carbon content?\n");
        scanf("%f",&y);
        printf("Enter tensile strength?\n");
        scanf("%d",&z);
        if (x>60&&y<0.7&&z>5000)
            printf("Grade is 10");
        else if(x>60&&y<0.7)
            printf("Grade is 9");
        else if(y<0.7&&z>5000)
            printf("Grade is 8");
        else if(x>60&&z>5000)
            printf("Grade is 7");
        else if(x>60||y<0.7||z>5000)
            printf("Grade is 6");
        else
            printf("Grade is 5");
        getch();
        }
        
        
  
  
  
  
  
  

Preliminary C programming

• Write a program to print "Hellow World".
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  printf("Hellow World");
  getch();
  }
• The length and height of a rectangle and radius of a circle are input through the keyboard.Write a program to find the area & perimeter of the rectangle and circumference of the circle.
  #include<stdio.h>
  #include<conio.h>
  
  void main()
  {
   clrscr();
   int length,height,area,per,rad,cir;
   printf("Enter a length? \n");
   scanf("%d",&length);
   printf("Enter a height? \n");
   scanf("%d",&height);
   printf("Enter a radius?\n");
   scanf("%d",&rad);
  
   area=length*height;
  
   per=2*(length+height);
   cir=2*3.1416*rad;
   printf("The perimiter is: %d\n",per);
  
   printf("The area is: %d\n",area);
   printf("The circumference is:%d",cir);
  
   getch();
   }
• Rahim's basic salary is inpute through the keyboard.His house rent allowarnce is 30% of his basic salary and medical allowance is 5% of basic salary.He gets extra 1000 tk as technical allowance.Write a program to calculate his gross salary and print the result.
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int b,t,g;
  float h,m;
  printf("input rahim's basic salary:\n");
  scanf("%d",&b);
  h=(b*30)/100;
  m=(b*5)/100;
  t=1000;
  g=(b)+(h)+(m)+(t);
  printf("Rahim's gross salary is:%d",g);
  getch();
  }
• Two anumbers  are input  through the keyboard into two locations A and B. Write a program to interchange the contents of A and B.
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int a,b,temp;
  printf("Enter the value of A:");
  scanf("%d",&a);
  printf("Enter the value of B:");
  scanf("%d",&b);
  temp=a;
  a=b;
  b=temp;
  
  printf("\n\nAfter interchange the value of A is:%d",a);
  printf("\n\nAfter interchange the value of B is:%d",b);
  getch();
  }
• If a 5 digit number is input  through the keyboard, Write a program to calculate  and print  the sum of its digits.
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int rem,sum=0;
  int num;
  printf("A 5 digit number is?\n");
  scanf("%d",&num);
  rem=num%10;
  sum=rem+sum;
  num=num/10;
  rem=num%10;
  sum=rem+sum;
  num=num/10;
  rem=num%10;
  sum=rem+sum;
  num=num/10;
  rem=num%10;
  sum=sum+rem;
  num=num/10;
  sum=sum+num;
  printf("\nThe sum of the digits of this number is:%d",sum);
  getch();
  }
• If  a 5 digit number is input  through the keyboard, Write a program to reverse the number.
  
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  long int rem,numb=0;
  long int num;
  printf("Enter the 5 digit number ?\n");
  scanf("%ld",&num);
  rem=num%10;
  numb=numb+(10000*rem);
  num=num/10;
  rem=num%10;
  numb=numb+(1000*rem);
  num=num/10;
  rem=num%10;
  numb=numb+(100*rem);
  num=num/10;
  rem=num%10;
  numb=numb+(10*rem);
  num=num/10;
  numb=numb+num;
  printf("The reverse number of this number is:%ld",numb);
  getch();
  }
• If  a 4 digit number is input  through the keyboard, Write a program to obtain the sum of the first and last digit of this number.
  #include<stdio.h>
  #include<conio.h>
  void main()
  {
  clrscr();
  int rem,sum=0;
  int num;
  printf("A 4 digit number is?\n");
  scanf("%d",&num);
  rem=num%10;
  sum=rem+sum;
  num=num/10;
  rem=num%10;
  num=num/10;
  rem=num%10;
  num=num/10;
  rem=num%10;
  sum=sum+rem;
  printf("\nThe sum of the first and last digit of this number is:%d",sum);
  getch();
  }