7407: Choose your own path(Problem J5)
内存限制:128 MB
时间限制:1.000 S
评测方式:文本比较
命题人:
提交:4
解决:2
题目描述
输入
输出
The output will be two lines. The first line will contain Y if all pages are reachable, and N otherwise.
The last line will contain a non-negative integer K, which is the shortest path a reader can take while reading this book. There will always be a finite shortest path.
The last line will contain a non-negative integer K, which is the shortest path a reader can take while reading this book. There will always be a finite shortest path.
样例输入 复制
3
2 2 3
0
1 1
样例输出 复制
Y
2
提示
Every page is reachable, since from page 1, we can reach pages 2 and 3. The shortest path is the
path 1 → 2, which contains two pages.