[BOJ] number-of-islands (Medium)

Author: jihostudy

김지호/4주차/260120.py

@@ -0,0 +1,47 @@
+# https://leetcode.com/problems/number-of-islands
+
+from typing import List
+from collections import deque
+
+class Solution:
+  def numIslands(self, grid: List[List[str]]) -> int:
+    N = len(grid)
+    M = len(grid[0])
+    
+ 
+    visited = [[False] * M for _ in range(N)]
+    
+    count = 0
+    for row in range(N):
+      for col in range(M):
+        if(visited[row][col] == False and grid[row][col] == '1') :
+          count += 1
+          self.BFS(grid,row,col,visited,N,M)
+    return count
+  
+  def BFS(self,grid,row,col,visited,N,M):
+    drow = [1,0,-1,0]
+    dcol = [0,-1,0,1]
+    
+    queue = deque()
+    queue.append([row,col])
+    visited[row][col] = True
+    
+    while(len(queue) != 0):
+      row, col = queue.popleft()
+      for i in range(4):
+        nrow = row + drow[i]
+        ncol = col + dcol[i]
+        if(0 <= nrow < N and 0 <= ncol < M and visited[nrow][ncol] == False and grid[nrow][ncol]=='1'):
+          queue.append([nrow,ncol])
+          visited[nrow][ncol] = True
+
+      
+        
+answer = Solution()
+print(answer.numIslands([
+  ["1","1","1","1","0"],
+  ["1","1","0","1","0"],
+  ["1","1","0","0","0"],
+  ["0","0","0","1","1"]
+]))