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。
CF1927A.Make it White
Make it White
You have a horizontal strip of cells. Each cell is either white or black.
You can choose a continuous segment of cells once and paint them all white. After this action, all the black cells in this segment will become white, and the white ones will remain white.
What is the minimum length of the segment that needs to be painted white in order for all cells to become white?
Input
The first line of the input contains a single integer () — the number of test cases. The descriptions of the test cases follow.
The first line of each test case contains a single integer () — the length of the strip.
The second line of each test case contains a string , consisting of characters, each of which is either 'W' or 'B'. The symbol 'W' denotes a white cell, and 'B' — a black one. It is guaranteed that at least one cell of the given strip is black.
Output
For each test case, output a single number — the minimum length of a continuous segment of cells that needs to be painted white in order for the entire strip to become white.
Note
In the first test case of the example for the strip "WBBWBW", the minimum length of the segment to be repainted white is . It is necessary to repaint to white the segment from the -nd to the -th cell (the cells are numbered from from left to right).
Samples
8
6
WBBWBW
1
B
2
WB
3
BBW
4
BWWB
6
BWBWWB
6
WWBBWB
9
WBWBWWWBW
4
1
1
2
4
6
4
7
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 |