N皇后问题。从函数c ++返回数组

Question

在尝试解决 c++ 中的 n-queens 问题时。我遇到了这个错误，我会得到正确的答案，但是当返回数组指针时，我最终得到的是垃圾数字而不是我的答案。关于这一点的奇怪部分是我使用递归来解决问题，并且只有在使用递归时才会得到垃圾编号（即使它正确地通过了递归）。数组在返回之前是完全正确的。

int* Successor(int board[], int n) {
    bool currentlyLegal = isLegalPosition(board, n);
    int firstZero = -1;
    int templast;

    for(int i = 0; i < n; i++) {
        if(board[i] == 0) {
            firstZero = i;
            break;
        }
    }

    if(currentlyLegal) {
        if(firstZero != -1) {
            for(int i = 1; i < n; i++) {
                board[firstZero] = i;
                if(isLegalPosition(board, n) && i != lastNum) {
                    return board;
                }
            }
            lastNum = -1;
            board[firstZero - 1] = 0;
            Successor(board, n);
        } else {
            templast = board[n - 1];
            for(int i = board[n - 1]; i < n; i++) {
                board[n - 1] = i;
                if(isLegalPosition(board, n) && i != board[n-1] && i != lastNum) {
                    return board;
                }
            }
            lastNum = templast;
            board[n - 1] = 0;
            Successor(board, n);
        }
    } else {
        if(firstZero != -1) {
            if(firstZero != 0) {
                for(int i = board[firstZero - 1]; i < n; i++) {
                    board[firstZero - 1] = i;
                    if(isLegalPosition(board, n) && i != board[firstZero - 1]) {
                        return board;
                    }
                }
                lastNum = -1;
                board[firstZero - 1] = 0;
                Successor(board, n);
            } else {
                board[0] = 1;
                return board;
            }
        } else {
            templast = board[n - 1];
            for(int i = board[n - 1]; i < n; n++) {
                board[n - 1] = i;
                if(isLegalPosition(board, n) && i != board[n - 1] && i != templast) {
                    return board;
                }
            }
            lastNum = templast;
            board[n - 1] = 0;
            Successor(board, n);
        }
    }

}

Answer 1

您的递归调用不会返回任何内容。打开所有警告后，您应该会看到“并非所有控制路径都返回值”的信息。将递归调用更改为

return Successor( board, n );