欢迎来到起遇信息学
起遇信息学正处于上线筹建阶段,以下功能已全部开放免费体验: ✅ 完整题库浏览与代码提交评测(C / C++ / Python / Java 等) ✅ 入门到进阶的系列课程试读、作业与考试 ✅ AI 提示、AI 作业分析等智能助教功能 ✅ 赛事模拟与个人能力报告 ✅ 邮箱注册开放 ⏳ 付费课程订阅与微信/支付宝支付通道 ⏳ 手机号登录,微信扫码登录、微信公众号绑定 使用中如遇任何问题,欢迎通过页面底部 **"联系我们"** 与我们沟通。
CF1713B.Optimal Reduction
Optimal Reduction
Consider an array of positive integers.
You may perform the following operation:
- select two indices and (), then
- decrease all elements by .
Let's call the minimum number of operations needed to change array into an array of zeros.
Determine if for all permutations of , is true.
An array is a permutation of an array if consists of the elements of in arbitrary order. For example, is a permutation of while is not a permutation of .
Input
The first line contains a single integer () — the number of test cases.
The first line of each test case contains a single integer () — the length of the array .
The second line contains integers () — description of the array .
It is guaranteed that the sum of over all test cases does not exceed .
Output
For each test case, print "YES" (without quotes) if for all permutations of , is true, and "NO" (without quotes) otherwise.
You can output "YES" and "NO" in any case (for example, strings "yEs", "yes" and "Yes" will be recognized as a positive response).
Note
In the first test case, we can change all elements to in operations. It can be shown that no permutation of requires less than operations to change all elements to .
In the third test case, we need operations to change all elements to , while only needs operations.
Samples
3
4
2 3 5 4
3
1 2 3
4
3 1 3 2
YES
YES
NO
在线编程 IDE
建议全屏模式获得最佳体验
| 进入全屏编程 | Alt+E |
| 递交评测 | Ctrl+Enter |
| 注释/取消注释 | Ctrl+/ |
| 缩放字体 | Ctrl+滚轮 |