200-Number-Of-Islands
Sat 17 May 2025
https://leetcode.com/problems/number-of-islands
import pyutil as pyu
pyu.get_local_pyinfo()
print(pyu.ps2("python-dotenv"))
from typing import List
class Solution:
def numIslands(self, grid: List[List[str]]) -> int:
m = len(grid)
n = len(grid[0])
dirs = [0, 1, 0, -1, 0]
def bfs(r, c):
q = deque([(r, c)])
grid[r][c] = '2' # Mark '2' as visited
while q:
i, j = q.popleft()
for k in range(4):
x = i + dirs[k]
y = j + dirs[k + 1]
if x < 0 or x == m or y < 0 or y == n:
continue
if grid[x][y] != '1':
continue
q.append((x, y))
grid[x][y] = '2' # Mark '2' as visited
ans = 0
for i in range(m):
for j in range(n):
if grid[i][j] == '1':
bfs(i, j)
ans += 1
return ans
new Solution().numIslands()
Score: 5
Category: leetcode