1.sum of even numbers 1 to n.

#include<stdio.h>
main()
{
    int i=1,n,sum=0;
    scanf("%d",&n);
    while(i<=n)
    {
        if(i%2==0)
        sum=sum+i;
         i++;
    }
    printf("sum of even numbers 1 to n is %d",sum);


return 0;
}