迷宫生成算法之一——prim算法python代码详解（One of the maze generation algorithm - prim algorithm Python code detail）

  1 import random
  2 import numpy as np
  3 from matplotlib import pyplot as plt
  4 import matplotlib.cm as cm
  5 
  6 # num_rows = int(input("Rows: "))  # number of rows
  7 # num_cols = int(input("Columns: "))  # number of columns
  8 num_rows = 4
  9 num_cols = 5
 10 
 11 # The array M is going to hold the array information for each cell.
 12 # The first four coordinates tell if walls exist on those sides
 13 # and the fifth indicates if the cell has been visited in the search.
 14 # M(LEFT, UP, RIGHT, DOWN, CHECK_IF_VISITED)
 15 M = np.zeros((num_rows, num_cols, 5), dtype=np.uint8)
 16 
 17 # The array image is going to be the output image to display
 18 image = np.zeros((num_rows * 10, num_cols * 10), dtype=np.uint8)
 19 
 20 # Set starting row and column
 21 r = 0
 22 c = 0
 23 history = [(r, c)]  # The history is the stack of visited locations
 24 
 25 # Trace a path though the cells of the maze and open walls along the path.
 26 # We do this with a while loop, repeating the loop until there is no history,
 27 # which would mean we backtracked to the initial start.
 28 trend = []
 29 while history:
 30     print("==================================================")
 31     # random choose a candidata cell from the cell set histroy
 32     r, c = random.choice(history)
 33     print("r = ", r)
 34     print("c = ", c)
 35     M[r, c, 4] = 1  # designate this location as visited
 36     history.remove((r, c))
 37     check = []
 38     # If the randomly chosen cell has multiple edges
 39     # that connect it to the existing maze,
 40     # c 大于0才有 左方向
 41     if c > 0:
 42         print("c > 0")
 43         print([r, c - 1, 4], M[r, c - 1, 4])
 44         # 等于1表示被访问过，找到已经被访问过的路径进行添加
 45         if M[r, c - 1, 4] == 1:
 46             check.append(‘L‘)
 47         # 等于0表示没有被访问过，那么就添加到需要访问history列表中，标记成2表示在history中将要被访问的，该值要与0和1不同，被访问后就会变成1。
 48         # 添加临近的单元格
 49         elif M[r, c - 1, 4] == 0:
 50             history.append((r, c - 1))
 51             M[r, c - 1, 4] = 2
 52     # r 大于0才有 上方向
 53     if r > 0:
 54         print("r > 0")
 55         print([r-1, c, 4], M[r-1, c, 4])
 56         if M[r - 1, c, 4] == 1:
 57             check.append(‘U‘)
 58         elif M[r - 1, c, 4] == 0:
 59             history.append((r - 1, c))
 60             M[r - 1, c, 4] = 2
 61     # c 小于 num_cols-1 才有 右方向
 62     if c < num_cols - 1:
 63         print("c < num_cols - 1")
 64         print([r, c + 1, 4], M[r, c + 1, 4])
 65         if M[r, c + 1, 4] == 1:
 66             check.append(‘R‘)
 67         elif M[r, c + 1, 4] == 0:
 68             history.append((r, c + 1))
 69             M[r, c + 1, 4] = 2
 70     # r 小于 num_rows-1 才有 下方向
 71     if r < num_rows - 1:
 72         print("r < num_rows - 1")
 73         print([r+1, c, 4], M[r+1, c, 4])
 74         if M[r + 1, c, 4] == 1:
 75             check.append(‘D‘)
 76         elif M[r + 1, c, 4] == 0:
 77             history.append((r + 1, c))
 78             M[r + 1, c, 4] = 2
 79 
 80     print("check = ", check)
 81     
 82     # select one of these edges at random.
 83     if len(check):
 84         move_direction = random.choice(check)
 85         print("move_direction = ", move_direction)
 86         trend.append([r, c, move_direction])
 87         if move_direction == ‘L‘:
 88             # 如果是往左走就标记index[0]=1，并且列数-1，然后标记右边被堵
 89             M[r, c, 0] = 1
 90             c = c - 1
 91             M[r, c, 2] = 1
 92         if move_direction == ‘U‘:
 93             # 如果是往上走就标记index[1]=1，并且行数-1，然后标记下方被堵
 94             M[r, c, 1] = 1
 95             r = r - 1
 96             M[r, c, 3] = 1
 97         if move_direction == ‘R‘:
 98             # 如果是往右走就标记index[2]=1，并且列数+1，然后标记左方被堵
 99             M[r, c, 2] = 1
100             c = c + 1
101             M[r, c, 0] = 1
102         if move_direction == ‘D‘:
103             # 如果是往下走就标记index[3]=1，并且行数+1，然后标记上方被堵
104             M[r, c, 3] = 1
105             r = r + 1
106             M[r, c, 1] = 1
107 
108 # Open the walls at the start and finish
109 M[0, 0, 0] = 1
110 M[num_rows - 1, num_cols - 1, 2] = 1
111 print(M)
112 # Generate the image for display
113 for row in range(0, num_rows):
114     for col in range(0, num_cols):
115         cell_data = M[row, col]
116         for i in range(10 * row + 2, 10 * row + 8):
117             image[i, range(10 * col + 2, 10 * col + 8)] = 255
118         if cell_data[0] == 1:
119             image[range(10 * row + 2, 10 * row + 8), 10 * col] = 255
120             image[range(10 * row + 2, 10 * row + 8), 10 * col + 1] = 255
121         if cell_data[1] == 1:
122             image[10 * row, range(10 * col + 2, 10 * col + 8)] = 255
123             image[10 * row + 1, range(10 * col + 2, 10 * col + 8)] = 255
124         if cell_data[2] == 1:
125             image[range(10 * row + 2, 10 * row + 8), 10 * col + 9] = 255
126             image[range(10 * row + 2, 10 * row + 8), 10 * col + 8] = 255
127         if cell_data[3] == 1:
128             image[10 * row + 9, range(10 * col + 2, 10 * col + 8)] = 255
129             image[10 * row + 8, range(10 * col + 2, 10 * col + 8)] = 255
130 
131 # Display the image
132 plt.imshow(image, cmap=cm.Greys_r, interpolation=‘none‘)
133 plt.show()
134 pass