2017 ACM Arabella Collegiate Programming Contest Magical Bamboos

Magical Bamboos

time limit per test
1.0 s

memory limit per test
256 MB

input
standard input

output
standard output

In a magical forest, there exists N bamboos that don't quite get cut down the way you would expect.

Originally, the height of the ith bamboo
is equal to hi.
In one move, you can push down a bamboo and decrease its height by one, but this move magically causes all the other bamboos to increase in height by one.

If you can do as many moves as you like, is it possible to make all the bamboos have the same height?

Input

The first line of input is T – the number of test cases.

The first line of each test case contains an integer N (1 ≤ N ≤ 105) -
the number of bamboos.

The second line contains N space-separated integers hi (1 ≤ hi ≤ 105) -
the original heights of the bamboos.

Output

For each test case, output on a single line "yes” (without quotes), if you can make all the bamboos have the same height, and "no" otherwise.

Example

input

2
3
2 4 2
2
1 2

output

yes
no

题意：给你n个数，每次将一个数减一，其他数加一，问经过几次操作后这n个数能否都相同

解题思路：将n个数排序后，相邻两个数的差为偶数即可

#include <iostream>
#include <cstdio>
#include <cstring>
#include <string>
#include <algorithm>
#include <cmath>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <vector>
#include <bitset>
#include <functional>

using namespace std;

#define LL long long
const int INF = 0x3f3f3f3f;

int n, h[100009];

int main()
{
int t;
scanf("%d", &t);
while (t--)
{
int flag = 1;
scanf("%d", &n);
for (int i = 1; i <= n; i++) scanf("%d", &h[i]);
sort(h + 1, h + 1 + n);
for (int i = 2; i <= n; i++)
if ((h[i] - h[i - 1]) % 2 != 0) flag = 0;
if(!flag) printf("no\n");
else printf("yes\n");
}
return 0;
}