시간 제한 | 메모리 제한 | 제출 | 정답 | 맞은 사람 | 정답 비율 |
---|---|---|---|---|---|
4 초 | 256 MB | 3 | 3 | 3 | 100.000% |
Takahashikun likes to paint floors. There is a floor divided into $N \times N$ grid, and some (possibly zero) cells may contain obstacles.
The information about the grid is given as $N$ strings $S_1, \ldots, S_N$. The $j$-th character of $S_i$ represents the cell $(i, j)$: '.
' and 's
' represent an empty cell, and '#
' represents a cell with obstacles.
There is excatly one cell with 's
'. First, Takahashikun enters the cell with 's
' and paints this cell. After that, he makes zero or more steps according to the following rule:
Determine if he can paint all cells without obstacles.
$N$
$S_1$
$S_2$
$\vdots$
$S_N$
Print "POSSIBLE
" if he can paint all cells without obstacles. Otherwise print "IMPOSSIBLE
".
.
', '#
', or 's
'.s
'..
'.5 #.... ..s.. ..#.. #.... ##..#
POSSIBLE
5 s.### ..### ###.. #.... #..##
IMPOSSIBLE