word-search

Author: freemjstudio

word-search/freemjstudio.py

@@ -0,0 +1,39 @@
+class Solution:
+    def exist(self, board: List[List[str]], word: str) -> bool:
+        answer = False
+
+        dx = [-1, 1, 0, 0]
+        dy = [0, 0, -1, 1]
+        n = len(board)
+        m = len(board[0])
+        visited = [[False] * m for _ in range(n)]
+
+        def dfs(x, y, visited, route):
+            nonlocal answer
+            if route == word:
+                answer = True
+                return
+            if (len(route) == len(word)) and route != word:
+                return
+
+            for i in range(4):
+                nx = x + dx[i]
+                ny = y + dy[i]
+
+                if 0 <= nx < n and 0 <= ny < m and not visited[nx][ny]:
+                    idx = len(route)
+                    if word[idx] == board[nx][ny]:
+                        visited[nx][ny] = True
+                        route += board[nx][ny]
+                        dfs(nx, ny, visited, route)
+                        visited[nx][ny] = False
+                        route = route[:-1]
+
+        for i in range(n):
+            for j in range(m):
+                if board[i][j] == word[0]:
+                    visited[i][j] = True
+                    dfs(i, j, visited, word[0])
+                    visited[i][j] = False
+
+        return answer