UVa 167 - The Sultan's Successors

经典“八皇后问题”，把所有情况全部遍历一遍，统计最大值即可。

代码如下：

#include <iostream>#include <cstring>#include <cstdlib>#include <cstdio>#include <cmath>using namespace std;int a[9][9], vis[3][20], save[9], n, tot;void search(int cur){    int i;    if(cur == 8)    {        int sum = 0;        for(i = 0; i < 8; i++)            sum += a[i][save[i]];        if(sum > tot)            tot = sum;        return ;    }    for(i = 0; i < 8; i++)    {        if(!vis[0][i] && !vis[1][cur + i] && !vis[2][cur - i + n])        {            save[cur] = i;            vis[0][i] = vis[1][cur + i] = vis[2][cur - i + n] = 1; // 用二维数组保存同对角线的情况            search(cur + 1);            vis[0][i] = vis[1][cur + i] = vis[2][cur - i + n] = 0;        }    }}int main(){#ifdef test    freopen("sample.txt", "r", stdin);#endif    scanf("%d", &n);    while(n--)    {        tot = 0;        memset(vis, 0, sizeof(vis));        for(int i = 0; i < 8; i++)            for(int j = 0; j < 8; j++)                scanf("%d", &a[i][j]);        search(0);        printf("%5d\n", tot);    }    return 0;}