init-commit

internbootcamp/libs/maze/maze_solver.py

@@ -0,0 +1,142 @@
+from collections import deque
+
+
+def solve_maze(maze, start_pos=(0, 0), end_pos=None):
+    """
+    使用广度优先搜索(BFS)求解迷宫
+
+    参数:
+        maze: 迷宫的二维数组（0 表示通路，1 表示墙）
+        start_pos: 起点位置，默认为(0, 0)
+        end_pos: 终点位置，默认为右下角
+
+    返回:
+        path: 从起点到终点的路径列表，如果没有路径则返回None
+        output: 详细的求解过程字符串
+    """
+    height = len(maze)
+    width = len(maze[0]) if height > 0 else 0
+
+    # 如果没有指定终点，默认为右下角
+    if end_pos is None:
+        end_pos = (height - 1, width - 1)
+
+    # 确保起点和终点坐标有效
+    start_x, start_y = start_pos
+    end_x, end_y = end_pos
+
+    if not (0 <= start_x < height and 0 <= start_y < width) or maze[start_x][start_y] == 1:
+        return None, "起点坐标无效或被墙壁阻挡"
+    if not (0 <= end_x < height and 0 <= end_y < width) or maze[end_x][end_y] == 1:
+        return None, "终点坐标无效或被墙壁阻挡"
+
+    # 定义移动方向：右、下、左、上
+    directions = [(0, 1), (1, 0), (0, -1), (-1, 0)]
+    direction_names = ["右", "下", "左", "上"]
+
+    # 使用BFS寻找路径
+    queue = deque([(start_x, start_y, [(start_x, start_y)])])  # 队列中存储当前点和路径
+    visited = set([(start_x, start_y)])  # 使用集合记录已访问的位置
+
+    output = "开始使用广度优先搜索(BFS)求解迷宫...\n\n"
+    output += f"起点: {start_pos}\n"
+    output += f"终点: {end_pos}\n\n"
+
+    step = 0
+
+    while queue:
+        step += 1
+        x, y, path = queue.popleft()
+
+        output += f"步骤 {step}:\n"
+        output += f"当前位置: ({x}, {y})\n"
+
+        if (x, y) == end_pos:  # 到达终点
+            output += "找到终点！\n"
+            output += f"路径长度: {len(path)}\n"
+            output += "完整路径:\n"
+            output += str(path)
+            return path, output
+
+        # 探索四个方向
+        for i, (dx, dy) in enumerate(directions):
+            nx, ny = x + dx, y + dy
+            if (0 <= nx < height and 0 <= ny < width and
+                    maze[nx][ny] == 0 and (nx, ny) not in visited):
+                visited.add((nx, ny))
+                queue.append((nx, ny, path + [(nx, ny)]))
+                output += f"  添加位置 ({nx}, {ny}) 到队列 (向{direction_names[i]})\n"
+
+        output += "\n"
+
+    output += "无法找到从起点到终点的路径。\n"
+    return None, output
+
+
+def is_path_exist(maze, start_pos=(0, 0), end_pos=None):
+    """
+    检查迷宫是否存在从起点到终点的路径（使用 BFS）
+
+    参数:
+        maze: 迷宫的二维数组
+        start_pos: 起点位置
+        end_pos: 终点位置
+
+    返回:
+        exists: 是否存在路径（True/False）
+    """
+    height = len(maze)
+    width = len(maze[0]) if height > 0 else 0
+
+    # 如果没有指定终点，默认为右下角
+    if end_pos is None:
+        end_pos = (height - 1, width - 1)
+
+    # 确保起点和终点坐标有效
+    start_x, start_y = start_pos
+    end_x, end_y = end_pos
+
+    if not (0 <= start_x < height and 0 <= start_y < width) or maze[start_x][start_y] == 1:
+        return False
+    if not (0 <= end_x < height and 0 <= end_y < width) or maze[end_x][end_y] == 1:
+        return False
+
+    # 定义移动方向：右、下、左、上
+    directions = [(0, 1), (1, 0), (0, -1), (-1, 0)]
+
+    # 使用BFS寻找路径
+    queue = deque([(start_x, start_y)])
+    visited = set([(start_x, start_y)])
+
+    while queue:
+        x, y = queue.popleft()
+
+        if (x, y) == end_pos:  # 到达终点
+            return True
+
+        for dx, dy in directions:
+            nx, ny = x + dx, y + dy
+            if (0 <= nx < height and 0 <= ny < width and
+                    maze[nx][ny] == 0 and (nx, ny) not in visited):
+                visited.add((nx, ny))
+                queue.append((nx, ny))
+
+    return False
+
+
+if __name__ == "__main__":
+    # 测试迷宫求解
+    maze = [
+        [0, 1, 0, 0, 0],
+        [0, 1, 0, 1, 0],
+        [0, 0, 0, 1, 0],
+        [1, 1, 1, 1, 0],
+        [0, 0, 0, 0, 0]
+    ]
+
+    path, output = solve_maze(maze)
+    print(output)
+
+    # 测试路径存在性检查
+    exists = is_path_exist(maze)
+    print(f"路径存在: {exists}")