upd

algorithms/labs/lab8/code/search/1.py

@@ -0,0 +1,38 @@
+def exist(board, word):
+    rows, cols = len(board), len(board[0])
+    visited = set()
+
+    def dfs(r, c, k):
+        if k == len(word):
+            return True
+        if (
+            r < 0
+            or r >= rows
+            or c < 0
+            or c >= cols
+            or (r, c) in visited
+            or board[r][c] != word[k]
+        ):
+            return False
+        visited.add((r, c))
+        ok = (
+            dfs(r + 1, c, k + 1)
+            or dfs(r - 1, c, k + 1)
+            or dfs(r, c + 1, k + 1)
+            or dfs(r, c - 1, k + 1)
+        )
+        visited.remove((r, c))
+        return ok
+
+    for r in range(rows):
+        for c in range(cols):
+            if dfs(r, c, 0):
+                return True
+    return False
+
+
+if __name__ == "__main__":
+    board = [["A", "B", "C", "E"], ["S", "F", "C", "S"], ["A", "D", "E", "E"]]
+    print(exist(board, "ABCCED"))
+    print(exist(board, "SEE"))
+    print(exist(board, "ABCB"))