HDU 2139 Calculate the formula

http://acm.hdu.edu.cn/showproblem.php?pid=2139

Problem Description

You just need to calculate the sum of the formula: 1^2+3^2+5^2+……+ n ^2.

 

Input

In each case, there is an odd positive integer n.

 

Output

Print the sum. Make sure the sum will not exceed 2^31-1

 

Sample Input

3

 

Sample Output

10

 

代码：

#include <bits/stdc++.h>
using namespace std;

const int maxn = 2345;
long long s[maxn];

int main() {
    int N;
    s[1] = 1;
    for(int i = 3; i <= maxn; i += 2)
        s[i] = s[i - 2] + i * i;

    while(~scanf("%d", &N)) {
        printf("%lld\n", s[N]);
    }

    return 0;
}