Poj Solution 2926

http://poj.org/problem?id=2926

#include <algorithm>
#include <cstdio>
#include <vector>
#include <map>
#include <stack>
#include <memory.h>
#include <math.h>
using namespace std;

double x[100000][5];

int main( ) {
    int n, i, k, j;
    int sign[5];
    double best = 0, min, max, t;
    scanf( "%d", &n );
    
    for( i=0; i<n; i++ )
        scanf( "%lf%lf%lf%lf%lf", x[i], x[i]+1, x[i]+2, x[i]+3, x[i]+4 );
        
    for( k=0; k<32; k++ ) {
        for( i=0; i<5; i++ )
            sign[i] = (k&(1<<i)) ? 1 : -1;
        min = 1e100, max = -1e100;
        for( i=0; i<n; i++ ) {
            t = 0;
            for( j=0; j<5; j++ )
                t += sign[j]*x[i][j];
            if( t > max )
                max = t;
            if( t < min )
                min = t;
        }
        if( max-min > best )
            best = max-min;
    }
    printf( "%.2lfn", best );
    return 0;
}