create dev channel

zeta/py/completed/3109.py

@@ -0,0 +1,45 @@
+def get_maximum_upper(R, C, M, start):
+    now_r = start
+    now_c = 0
+    D = [(now_r, now_c)]
+    dir = [(-1, 1), (0, 1), (1, 1)]
+    while D:
+        now_r, now_c = D.pop()
+        M[now_r][now_c] = 1
+        insert = []
+        for dr, dc in dir:
+            new_r, new_c = now_r + dr, now_c + dc
+            if new_c == C - 1:
+                if 0 <= new_r < R:
+                    M[new_r][new_c] = 1
+                    return True
+                continue
+
+            if 0 <= new_r < R:
+                if M[new_r][new_c]:
+                    continue
+                insert.append((new_r, new_c))
+        if insert:
+            D.extend(insert[::-1])
+    return []
+
+
+def solve(R, C, M):
+    cnt = 0
+    for i in range(R):
+        path = get_maximum_upper(R, C, M, i)
+        if path:
+            cnt += 1
+        else:
+            continue
+
+    return cnt
+
+
+if __name__ == '__main__':
+    import sys
+
+    R, C = map(int, sys.stdin.readline().split())
+    M = [list(map(lambda x: 1 if x == "x" else 0, sys.stdin.readline().rstrip())) for _ in range(R)]
+
+    print(solve(R, C, M))