UVA 167 The Sultan's Successors (UVALive 5227, SCU 1033, HDU 1642, Regionals 1991 >> South Pacific)

///     Raihan Ruhin
///     CSE, Jahangirnagar University.
///     Dhaka-Bangladesh.
///     id: raihanruhin (topcoder / codeforces / codechef / uva), 3235 (lightoj)
///     mail: raihanruhin@ (yahoo / gmail / facebook)
///     blog: ruhinraihan.blogspot.com

#include<bits/stdc++.h>
using namespace std;

#define SET(a) memset(a,-1,sizeof(a))
#define CLR(a) memset(a,0,sizeof(a))
#define PI acos(-1.0)

#define MOD 1000000007
#define MX 100010

int mat[10][10], mx, n;
bool board[10][10];

bool isSafe(int row, int col)
{
    //left
    for(int i=0;i<col;i++)
        if(board[row][i])   return false;
    //upper left
    for(int i=row, j=col;i>=0 && j>=0;i--, j--)
        if(board[i][j])     return false;
    //bottom left
    for(int i=row, j=col;i<n && j>=0;i++, j--)
        if(board[i][j])     return false;
return true;
}

void solveNQ(int col)
{
    if(col>=n)
    {
        int sum=0;
        for(int i=0;i<n;i++)
            for(int j=0;j<n;j++)
                if(board[i][j])
                    sum+=mat[i][j];
        mx=max(mx, sum);
    }

    for(int i=0;i<n;i++)
        if(isSafe(i, col))
        {
            board[i][col]=true;
            solveNQ(col+1);
            board[i][col]=false;
        }
return;
}

int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);
    int kk=1, tc, m;
    n=8;
    string s;
    cin>>tc;
    while(tc--)
    {
        for(int i=0;i<n;i++)
            for(int j=0;j<n;j++)
                cin>>mat[i][j];
        CLR(board);
        mx=0;
        solveNQ(0);
        //cout<<"Case "<<kk++<<": "<< mx <<"\n";
        cout<<setw(5)<<mx<<"\n";
    }

    return 0;
}