描述過幾天再寫，先放代碼
DFS
#!/usr/bin/python
# -*- coding: utf-8 -*-
'''
狀態表示方式（M，C，B）
M：修道士(Missionaries)在左岸的數量
C：野人(Cannibals)在左岸的數量
B：船的狀態，左岸還是右岸
初始狀態（3，3，1）
終結狀態（0，0，0）
'''
open_list = []
close_list = []
str_end = "0-0-0"
global time
time = 0
def init_list(list_path):
for i in range(0, 1000):
list_path.append(0)
def hund(M, C, boat):
return (M+1) * 100 + (C+1) * 10 + (boat+1)
def re_back(n):
a = n // 100
b = n // 10 % 10
c = n % 10
return[a - 1, b - 1, c - 1]
def print_list(list_path, n):
if list_path[n] == 442:
print(re_back(442))
print(re_back(n))
return
else:
print_list(list_path, list_path[n])
print(re_back(n))
def DFS():
global time
time += 1
if len(open_list) == 0:
return
list_temp = open_list.pop()
M = list_temp[0]
C = list_temp[1]
boat = list_temp[2]
str_temp = str(M) + '-' + str(C) + '-' + str(boat)
close_list.append(list_temp)
if str_temp == str_end:
print("OK")
print_list(list_path, 111)
return
if (M < 0) | (C < 0) | (M > 3) | (C > 3):
return
if (M & (M < C)) | ((3 - M) & ((3 - M) < (3 - C))):
return
#print(time)
#print(list_temp)
fa_node = hund(M, C, boat)
if boat == 1: # 左岸，人應該減少
boat = 0
if ([M - 2, C, boat] not in open_list) & ([M - 2, C, boat] not in close_list):
open_list.append([M - 2, C, boat])
list_path[hund(M - 2, C, boat)] = fa_node
DFS()
if ([M, C - 2, boat] not in open_list) & ([M, C - 2, boat] not in close_list):
open_list.append([M, C - 2, boat])
list_path[hund(M, C - 2, boat)] = fa_node
DFS()
if ([M - 1, C, boat] not in open_list) & ([M - 1, C, boat] not in close_list):
open_list.append([M - 1, C, boat])
list_path[hund(M - 1, C, boat)] = fa_node
DFS()
if ([M - 1, C - 1, boat] not in open_list) & ([M - 1, C - 1, boat] not in close_list):
open_list.append([M - 1, C - 1, boat])
list_path[hund(M - 1, C - 1, boat)] = fa_node
DFS()
if ([M, C - 1, boat] not in open_list) & ([M, C - 1, boat] not in close_list):
open_list.append([M, C - 1, boat])
list_path[hund(M, C - 1, boat)] = fa_node
DFS()
else:
boat = 1 # 右岸，人應該增加
if ([M + 2, C, boat] not in open_list) & ([M + 2, C, boat] not in close_list):
open_list.append([M + 2, C, boat])
list_path[hund(M + 2, C, boat)] = fa_node
DFS()
if ([M, C + 2, boat] not in open_list) & ([M, C + 2, boat] not in close_list):
open_list.append([M, C + 2, boat])
list_path[hund(M, C + 2, boat)] = fa_node
DFS()
if ([M + 1, C, boat] not in open_list) & ([M + 1, C, boat] not in close_list):
open_list.append([M + 1, C, boat])
list_path[hund(M + 1, C, boat)] = fa_node
DFS()
if ([M + 1, C + 1, boat] not in open_list) & ([M + 1, C + 1, boat] not in close_list):
open_list.append([M + 1, C + 1, boat])
list_path[hund(M + 1, C + 1, boat)] = fa_node
DFS()
if ([M, C + 1, boat] not in open_list) & ([M, C + 1, boat] not in close_list):
open_list.append([M, C + 1, boat])
list_path[hund(M, C + 1, boat)] = fa_node
DFS()
if __name__ == "__main__":
list_path = []
init_list(list_path)
str_first = str(3) + '-' + str(3) + '-' + str(1)
#print("初始狀態：" + str_first)
open_list.append([3, 3, 1])
DFS()
#print(time)
BFS
#!/usr/bin/python
# -*- coding: utf-8 -*-
'''
狀態表示方式（M，C，B）
M：修道士(Missionaries)在左岸的數量
C：野人(Cannibals)在左岸的數量
B：船的狀態，左岸還是右岸
初始狀態（3，3，1）
終結狀態（0，0，0）
'''
def init_list(list_path):
for i in range(0, 1000):
list_path.append(0)
def hund(M, C, boat):
return (M+1) * 100 + (C+1) * 10 + (boat+1)
def re_back(n):
a = n // 100
b = n // 10 % 10
c = n % 10
return[a - 1, b - 1, c - 1]
def print_list(list_path, n):
if list_path[n] == 442:
print(re_back(442))
print(re_back(n))
return
else:
print_list(list_path, list_path[n])
print(re_back(n))
if __name__ == "__main__":
open_list = []
close_list = []
list_path = []
time = 0 # 步驟計數
str_end = "0-0-0"
str_first = str(3) + '-' + str(3) + '-' + str(1)
#print("初始狀態：" + str_first)
open_list.append([3,3,1])
time += 1
init_list(list_path)
while len(open_list) != 0:
#print(time)
time += 1
list_temp = open_list.pop(0)
M = list_temp[0]
C = list_temp[1]
boat = list_temp[2]
str_temp = str(M) + '-' + str(C) + '-' + str(boat)
close_list.append(list_temp)
if str_temp == str_end:
print("OK")
print_list(list_path, 111)
break
if (M < 0) | (C < 0) | (M > 3) | (C > 3):
continue
if (M & (M < C)) | ((3 - M) & ((3 - M) < (3 - C))):
continue
#print(list_temp)
fa_node = hund(M, C, boat)
if boat == 1: # 左岸，人應該減少
boat = 0
if ([M-2,C,boat] not in open_list) & ([M-2,C,boat] not in close_list):
open_list.append([M-2,C,boat])
list_path[hund(M-2, C, boat)] = fa_node
if ([M,C-2,boat] not in open_list) & ([M,C-2,boat] not in close_list):
open_list.append([M,C-2,boat])
list_path[hund(M, C - 2, boat)] = fa_node
if ([M-1,C,boat] not in open_list) & ([M-1,C,boat] not in close_list):
open_list.append([M-1,C,boat])
list_path[hund(M - 1, C, boat)] = fa_node
if ([M-1,C-1,boat] not in open_list) & ([M-1,C-1,boat] not in close_list):
open_list.append([M-1,C-1,boat])
list_path[hund(M - 1, C - 1, boat)] = fa_node
if ([M,C-1,boat] not in open_list) & ([M,C-1,boat] not in close_list):
open_list.append([M,C-1,boat])
list_path[hund(M, C - 1, boat)] = fa_node
else:
boat = 1 #右岸，人應該增加
if ([M+2,C,boat] not in open_list) & ([M+2,C,boat] not in close_list):
open_list.append([M+2,C,boat])
list_path[hund(M + 2, C, boat)] = fa_node
if ([M,C+2,boat] not in open_list) & ([M,C+2,boat] not in close_list):
open_list.append([M,C+2,boat])
list_path[hund(M, C + 2, boat)] = fa_node
if ([M+1,C,boat] not in open_list) & ([M+1,C,boat] not in close_list):
open_list.append([M+1,C,boat])
list_path[hund(M + 1, C, boat)] = fa_node
if ([M+1,C+1,boat] not in open_list) & ([M+1,C+1,boat] not in close_list):
open_list.append([M+1,C+1,boat])
list_path[hund(M + 1, C + 1, boat)] = fa_node
if ([M,C+1,boat] not in open_list) & ([M,C+1,boat] not in close_list):
open_list.append([M,C+1,boat])
list_path[hund(M, C + 1, boat)] = fa_node