YTU 2905: The Sum of 1...N

2905: The Sum of 1...N

时间限制: 1 Sec  内存限制: 128 MB

提交: 281  解决: 51

题目描述

Given an integer n,your task is to calculate 1+2+...+N;

输入

The first line of input contains an integer T, indicating the number of test cases (T<=20)

The each test case contains a single positive integer N(N<=2^32).

输出

For each input you should output the sum of 1+2+...+N in one line.(The result must less than 2^63)

样例输入

2101

样例输出

551

im0qianqian_站在回忆的河边看着摇晃的渡船终年无声地摆渡,它们就这样安静地画下黄昏画下清晨......

#include <iostream>
using namespace std;
int main()
{
    unsigned long long n;
    int T;
    cin>>T;
    while(T--)
    {
        cin>>n;
        n=n*(n+1)/2;
        cout<<n<<endl;
    }
    return 0;
}