[baekjoon]python #2589 보물섬

 

2589번: 보물섬

from collections import deque
col,row = map(int,input().split())
arr = [list(map(str,input())) for _ in range(col)]

Max = 0

def bfs(y,x,move):
    global Max
    q = deque()
    q.append((y,x,move))
    visit = [[0] * row for _ in range(col)]
    visit[y][x] = 1

    while q:
        ny,nx,nmove = q.popleft()

        if Max < nmove:
            Max = nmove

        directy=[-1,1,0,0]
        directx=[0,0,-1,1]
        for i in range(4):
            dy = directy[i]+ny
            dx = directx[i]+nx

            if 0<=dy<col and 0<=dx<row:
                if visit[dy][dx] == 0 and arr[dy][dx]=='L':
                    visit[dy][dx]=nmove
                    q.append((dy,dx,nmove+1))

for i in range(col):
    for j in range(row):
        if arr[i][j] == 'L':
            bfs(i,j,1)

print(Max-1)

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