N皇后问题：溯搜索算法完整python代码

N皇后问题是经典的回溯法问题，它涉及在一个n×n的棋盘上放置n个皇后，使得任意两个皇后都不会在同一行、同一列，以及对角线上。以下是使用Python实现的完整溯搜索算法：

def is_safe(board, row, col):
    # 检查列是否冲突
    for i in range(row):
        if board[i] == col:
            return False

    # 检查左上方对角线是否冲突
    for i, j in zip(range(row, -1, -1), range(col, -1, -1)):
        if board[i] == j:
            return False

    # 检查右上方对角线是否冲突
    for i, j in zip(range(row, n, 1), range(col, n, 1)):
        if board[i] == j:
            return False
    return True

def solve_n_queens(n):
    def place_queen(board, col):
        if col >= n:
            solutions.append(list(board))
            return
        for row in range(n):
            if is_safe(board, row, col):
                board[row] = col
                place_queen(board, col + 1)
                board[row] = -1

    board = [-1] * n
    solutions = []
    place_queen(board, 0)
    return solutions

# 测试代码
n = 4
solutions = solve_n_queens(n)
for solution in solutions:
    print(solution)