Submission #31377156

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Source Code Expand

from collections import deque
h, w = map(int, input().split())
s = [""] * h
for i in range(h):
    s[i] = input()
DI = [0, -1, 0, 1]
DJ = [-1, 0, 1, 0]
dist = [[-1] * w for i in range(h)]
q = deque()
for i in range(h):
    for j in range(w):
        if s[i][j] == "#":
            dist[i][j] = 0
            q.append([i, j])
def push(i2, j2, d):
    if i2 < 0 or h <= i2 or j2 < 0 or w <= j2:
        return
    if dist[i2][j2] != -1:
        return
    dist[i2][j2] = d + 1
    q.append([i2, j2])
answer = 0
while len(q) != 0:
    i, j = q.popleft()
    answer = max(answer, dist[i][j])
    for k in range(4):
        push(i + DI[k], j + DJ[k], dist[i][j])
print(answer)

Submission Info

Judge Result