UVa 167 - The Sultan's Successors

/*
八皇后问题两种方法实现,参考《算法竞赛入门经典》
*/
#include <cstdio>
#include <cstring>
#include <iostream>
using namespace std;

const int MAX = 8;
const int RESULT = 100;
int row[MAX];
int save[RESULT][MAX];
int cur = 0;
int m[MAX][MAX];
int visit[3][MAX*2]  = {0};

bool ok(int x, int y)
{
for(int i=0; i<x; i++) {
if(row[i]==y || row[i]+i==x+y || row[i]-i==y-x) return false;
}
return true;
}

void dfs2(int level)
{
if(level == MAX) {
memcpy(save[cur], row, sizeof(row));
cur++;
return;
}
for(int i=0; i<MAX; i++) {
if(ok(level, i)) {
row[level] = i;
dfs2(level+1);
}
}
}

void dfs(int level)
{
if(level == MAX) {
memcpy(save[cur], row, sizeof(row));
cur++;
return;
}
for(int i=0; i<MAX; i++) {
if(!visit[0][i] && !visit[1][i+level] && !visit[2][level-i+MAX-1]) {
visit[0][i] = visit[1][i+level] = visit[2][level-i+MAX-1] = 1;
row[level] = i;
dfs(level+1);
visit[0][i] = visit[1][i+level] = visit[2][level-i+MAX-1] = 0;
}
}
}

int main()
{
#ifndef ONLINE_JUDGE
freopen("in.txt", "r", stdin);
#endif
//dfs(0);
dfs2(0);
int k;
scanf("%d", &k);
while(k--) {
for(int i=0; i<MAX; i++) {
for(int j=0; j<MAX; j++) {
scanf("%d", &m[i][j]);
}
}
int max_score = 0;
for(int i=0; i<cur; i++) {
int sum = 0;
for(int j=0; j<MAX; j++) {
sum += m[j][save[i][j]];
}
if(sum > max_score) max_score = sum;
}
printf("%5d\n", max_score);
}
return 0;
}