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。
CF2154A.Notelock
Notelock
Teto is playing the hit rhythm game osu!. The game can be described by a binary string of length and a positive integer where the following will happen in order:
- You will choose some positions in to protect.
- Then for each () in increasing order, Teto can set to
0if all the following are true:- ,
- is not protected,
- the previous elements do not contain
1. More formally,1does not occur in .
You dislike Teto (for some reason). So determine the minimum number of positions you need to protect to force her to leave unchanged.
A binary string is a string that only consists of characters 0 and 1.
Input
Each test contains multiple test cases. The first line contains the number of test cases (). The description of the test cases follows.
The first line of each testcase contains integers and (; ) — the length of and .
The second line of each test case contains a binary string of length consisting of characters 0 and 1.
The sum of across all testcases does not exceed .
Output
For each testcase, output the minimum number of positions you need to protect to force Teto to leave the string unchanged.
Note
For the first testcase, you can protect the first element and have: . Now Teto cannot change because it is protected and cannot change because . It can be proven this is optimal.
For the second testcase, you can protect only the first element and have . Teto cannot change because it is protected and she cannot change because there is 1 in the previous elements ().
For the fourth testcase, you must protect and have $s = \mathtt{\color{red}{1}0\color{red}{1}0\color{red}{1}0\color{red}{1}}$. It can be shown that this is optimal. For example, if you did not protect , then Teto can change it to 0 (\color{red}{1}\color{blue}{0}10\color{red}{1}0\color{red}{1})
Samples
9
2 2
11
6 6
100001
5 3
10000
7 2
1010101
7 4
0000001
3 3
010
3 2
011
7 4
1001001
8 3
00000000
1
1
1
4
1
1
1
1
0
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 |