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。
CF1692B.All Distinct
All Distinct
Sho has an array consisting of integers. An operation consists of choosing two distinct indices and and removing and from the array.
For example, for the array , Sho can choose to remove indices and . After this operation, the array becomes . Note that after any operation, the length of the array is reduced by two.
After he made some operations, Sho has an array that has only distinct elements. In addition, he made operations such that the resulting array is the longest possible.
More formally, the array after Sho has made his operations respects these criteria:
- No pairs such that () and exist.
- The length of is maximized.
Output the length of the final array.
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 of each test case contains integers () — the elements of the array.
Output
For each test case, output a single integer — the length of the final array. Remember that in the final array, all elements are different, and its length is maximum.
Note
For the first test case Sho can perform operations as follows:
- Choose indices and to remove. The array becomes .
- Choose indices and to remove. The array becomes .
The final array has a length of , so the answer is . It can be proven that Sho cannot obtain an array with a longer length.
For the second test case Sho can perform operations as follows:
- Choose indices and to remove. The array becomes .
- Choose indices and to remove. The array becomes .
The final array has a length of , so the answer is . It can be proven that Sho cannot obtain an array with a longer length.
Samples
4
6
2 2 2 3 3 3
5
9 1 9 9 1
4
15 16 16 15
4
10 100 1000 10000
2
1
2
4
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 |