UVa 167 - The Sultan's Successors

#include <iostream>
#include <cstdlib>
#include <cstdio>

using namespace std;

int maps[8][8];
int smap[8][8];
int max_sum;

void change( int x, int y, int dx, int dy )
{
	int id = x+1; 
	while ( x < 8 && x >= 0 && y < 8 && y >= 0 ) {
		if ( !smap[x][y] ) 
			smap[x][y] = id;
		else if ( smap[x][y] == id ) 
			smap[x][y] = 0; 
		x += dx; y += dy;
	}
}

void dfs( int x, int v )
{
	if ( x == 8 ) {
		if ( max_sum < v ) max_sum = v;
		return;
	}
	for ( int i = 0 ; i < 8 ; ++ i )
		if ( !smap[x][i] ) {
			change( x, i, 1, 0 );
			change( x, i, 1, 1 );
			change( x, i, 1,-1 );
			dfs( x+1, v+maps[x][i] );
			change( x, i, 1, 0 );
			change( x, i, 1, 1 );
			change( x, i, 1,-1 );
		}
}

int main()
{
	int n;
	while ( ~scanf("%d",&n) ) 
	for ( int t = 1 ; t <= n ; ++ t ) {
		for ( int i = 0 ; i < 8 ; ++ i )
		for ( int j = 0 ; j < 8 ; ++ j ) {
			scanf("%d",&maps[i][j]);
			smap[i][j] = 0;
		}
		
		max_sum = 0;
		dfs(0, 0);
		printf("%5d\n",max_sum);
	}
	return 0;
}