hdu2114

Calculate S(n)

Problem Description

Calculate S(n).

S(n)=1³+2³ +3³ +......+n³ .

 

Input

Each line will contain one integer N(1 < n < 1000000000). Process to end of file.

 

Output

For each case, output the last four dights of S(N) in one line.

 

Sample Input

1 2

 

Sample Output

0001 0009

主要是计算前n项和的公式。

前n项和的立方公式为   ： s(n)=（n*(n+1)/2）^2;

 

前n项和的平方公式为：s(n)=n*(n+1)(2*n+1)/6;

#include<cstdio>
#include<iostream>
using namespace std;
int main()
{
    long long n,sum,t,i;
    sum=0;
    while(cin>>n)
    {
        long long sum=(((n%10000)*(n+1)%10000)/2)*(((n%10000)*(n+1)%10000)/2)%10000;
        printf("%04I64d\n",sum);
    }
}