solution of TRICOUNT - Counting Triangles on spoj

 

TRICOUNT - Counting Triangles

solution-

#include<stdio.h>

int main()

{

    int t;

    scanf("%d",&t);

    while(t--)

    {

        long long unsigned num,sum;

        scanf("%llu",&num);

        if(num%2==0)

        sum=(num*(num+2)*((2*num)+1))/8;

        else

        sum=((num*(num+2)*((2*num)+1))-1)/8;

        printf("%llu\n",sum);

    }

    return 0;

}