Tinkoff Challenge - Elimination Round
B
Igor and his way to work
Codeforces
1600
原题
← AC →
翻译中…

Woken up by the alarm clock Igor the financial analyst hurried up to the work. He ate his breakfast and sat in his car. Sadly, when he opened his GPS navigator, he found that some of the roads in Bankopolis, the city where he lives, are closed due to road works. Moreover, Igor has some problems with the steering wheel, so he can make no more than two turns on his way to his office in bank.

翻译中…

Bankopolis looks like a grid of $*n*$ rows and $*m*$ columns. Igor should find a way from his home to the bank that has no more than two turns and doesn't contain cells with road works, or determine that it is impossible and he should work from home. A turn is a change in movement direction. Igor's car can only move to the left, to the right, upwards and downwards. Initially Igor can choose any direction. Igor is still sleepy, so you should help him.

翻译中…

Input

翻译中…

The first line contains two integers $*n*$ and $*m*$ ($1 ≤ *n*, *m* ≤ 1000$) — the number of rows and the number of columns in the grid.

翻译中…

Each of the next $*n*$ lines contains $*m*$ characters denoting the corresponding row of the grid. The following characters can occur:

翻译中…
  • "." — an empty cell;
  • "*" — a cell with road works;
  • "S" — the cell where Igor's home is located;
  • "T" — the cell where Igor's office is located.
翻译中…

It is guaranteed that "S" and "T" appear exactly once each.

翻译中…

Output

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In the only line print "YES" if there is a path between Igor's home and Igor's office with no more than two turns, and "NO" otherwise.

翻译中…

Note

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The first sample is shown on the following picture:

翻译中…

image

翻译中…

In the second sample it is impossible to reach Igor's office using less that $4$ turns, thus there exists no path using no more than $2$ turns. The path using exactly $4$ turns is shown on this picture:

翻译中…

image

翻译中…

样例

Input #1
5 5
..S..
****.
T....
****.
.....
Output #1
YES
InputCopy OutputCopy
Input #2
5 5
S....
****.
.....
.****
..T..
Output #2
NO
InputCopy OutputCopy
题目信息
题号
793B
时间限制
3 s
内存限制
256 MB
标签
DFS 及类似
图论
模拟
最短路

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。