為什么我的代碼對N個皇后不起作用？

Question

我得到了這段代碼，基本上如果我輸入：0 1，那么將在這個稱為棋盤的鄰接矩陣上將0 1分配給位置0 1。問題是尺寸為4x4的棋盤，如果我輸入

1 0, 
3 1,
0 2,
2 3 

它應該輸出

[[0, 0, 1, 0], [1, 0, 0, 0], [0, 0, 0, 1], [0, 1, 0, 0]]

但我收到“ int”對象錯誤，此行不支持項目分配：

chessboard[pos[0]][pos[1]] = 1

這是我的代碼。

N = int ( input (" Enter N: ") ) # Makes an empty chessboard of size N by N
chessboard = N*[0]
for row in range (N) :
    chessboard[row]=N*[0]
    print(chessboard)
    # This while loop asks the user for input N times and checks that it ’s     validity and places the queens
    inputCount = 0
    while inputCount < N:
         pos = input (" Please input the Queen position ")
        pos = pos.split () # Cast the input as integers
        pos [0] = int (pos [0])
        pos [1] = int (pos [1])
# If the input is out of range , inform the user , decrement the counter set the input to 0 1
    if pos [0] < 0 or pos [0] >N-1 or pos [1] < 0 or pos [1] >N-1:
        print (" Invalid position ")
        pos [0] = pos [1] = 0
        inputCount=inputCount-1
    else :# Uses the input to place the queens
        chessboard[pos[0]][pos[1]] = 1
    inputCount += 1
print ( chessboard )

Answer 1

chessboard = N*[0]
for row in range (N) :
    chessboard[row]=N*[0]
    print(chessboard)

    # here you're still in the chessboard init loop

    inputCount = 0
    while inputCount < N:

您正在初始化chessboard開始處理， 而不是在開始之后。

由於國際chessboard首先是一個整數列表（為什么？），由循環中的整數列表取代，而您的循環僅執行第一次迭代，因此會出現此錯誤。

您需要取消縮進print(chessboard)

但最好不要這樣循環就初始化chessboard （在外循環中使用列表推導而不是乘法來生成每一行的單獨引用）：

chessboard = [[0]*N for _ in range(N)]