Codeforces Round 892 (Div. 2) C. Another Permutation Problem 纯数学方法 思维题

Codeforces Round 892 (Div. 2) C. Another Permutation Problem

源码：

#include <iostream>
#include <algorithm>
#include <set>
#include <map>
#include <queue>
#include <vector>
#include <stack>
#include <cstdio>
#include <cstring>
#include <cstdlib>
using namespace std;
const int maxn = 550;
long long s[maxn];int main(){int t;cin >> t;while(t--){long long n;cin >> n;long long ans = 0;s[0] = 0;for(long long i = 1;i <= n;i++){s[i] = s[i-1]+i*i;}for(long long i = 1;i <= n;i++){long long sum = s[i-1];long long maxl = 0;long long temp;for(long long j = i;j <= n;j++){temp = (n-(j-i))*j;sum += temp;if(temp>maxl){maxl = temp;}}sum -= maxl;if(sum>ans){ans = sum;}}cout << ans << endl;}return 0;
}