Examples of C part 16 sum of N number

               Sum of n number
Program :

#include<stdio.h>
main()
{
  int i,n,sum=0;
  printf("Enter a number\n");
  scanf("%d",&n);
  for(i=0;i<=n;i++)
  {
    sum=sum+i;
  }
  printf("%d\n",sum);
}

Output:
Enter a number
10
55Explanation:

1. First we initialized i,n, and sum which is declared as zero.
2. A number is given by user (say 5).
3. Now the logic is:sum=sum+i
   • sum=0+0=0
   • for next iteration i becomes '1' so sum=0+1=1
   • for next iteration i becomes '2' so sum=2+1=3
   • for next iteration i becomes '3' so sum=3+3=6
   • for next iteration i becomes '4' so sum=4+6=10
   • for next iteration i becomes '5' so sum=10+5=15
   • for next iteration i becomes '6' which is not less than or equal to 'n'(i.e 5 as we took a value for explanation) then the loop terminates and goes to the next line.
4. Then the value of sum which is '15' will be printed.