word-search solution

Author: sejineer

word-search/sejineer.py

@@ -0,0 +1,33 @@
+"""
+시간 복잡도: O(N * M * 4^(word_len))
+공간 복잡도: O(word_len) 재귀 스택 최대 깊이 word_len
+"""
+from collections import deque
+
+class Solution:
+    def exist(self, board: List[List[str]], word: str) -> bool:
+        n, m = len(board), len(board[0])
+        word_len = len(word)
+
+        def dfs(x: int, y: int, idx: int) -> bool:
+            if idx == word_len:
+                return True
+            if x < 0 or y < 0 or x >= m or y >= n:
+                return False
+            if board[y][x] != word[idx]:
+                return False
+            
+            tmp, board[y][x] = board[y][x], '#'
+            for dx, dy in ((1, 0), (-1, 0), (0, 1), (0, -1)):
+                if dfs(x + dx, y + dy, idx + 1):
+                    return True
+
+            board[y][x] = tmp
+            return False
+        
+        for i in range(n):
+            for j in range(m):
+                if board[i][j] == word[0] and dfs(j, i, 0):
+                    return True
+        
+        return False