顺便把这个代码也放下出来吧 具体原理大家百度去~

// 查找(位运算方法)
int sum = 0, upperlimit = 1,p;
public void search3(int row, int ld, int rd)
    {
        if (row != upperlimit)
        {
            int pos = upperlimit & ~(row | ld | rd);
            while (pos != 0)
            {
                p = pos & -pos;
                pos -= p;
                search3(row + p, (ld + p) << 1, (rd + p) >> 1);
            }
        }
        else
        {
            sum++;
        }
    }

main

upperlimit = (upperlimit << q.n) - 1;
search3(0, 0, 0);