八皇后问题——全排列解法

#include <iostream>
#include<algorithm>
using namespace std;
string s[1000000];
int num[9] = {1,2,3,4,5,6,7,8,9};
int main()
{
    int x;
    cin >> x;
    if (x == 1)
    {
        cout << "Q" << endl;
    }
    
    else
    {
        int e = 0;
        do
        {
            for (int i = 0; i < x; i++)
            {
                s[e] += (num[i] + '0');
            }
            e++;
        } while (next_permutation(num, num + x));
        int n = 0;
        for (int i = e - 1; i >= 0; i--)
        {
            bool b = true;
            for (int y = 0; y < x - 1; y++)
            {
                for (int z = y + 1; z < x; z++)
                {
                    if (int(s[i][y]) == int(s[i][z]) + (z-y))
                    {
                        b = false;
                        break;
                    }
                    else if (int(s[i][y]) == int(s[i][z]) - (z-y))
                    {
                        b = false;
                        break;
                    }
                }
                if (!b) break;
            }
            if (b)
            {
                for (int t = 0; t < x; t++)
                {
                    for (int y = 0; y < x; y++)
                    {
                        if (y == int(s[i][t]) - 49)
                        {
                            cout << "Q";
                        }
                        else
                        {
                            cout << ".";
                        }
                    }

                    cout << endl;

                }
                cout << endl;
            }

        }
    }
    
}