AtCoder Beginner Contest 178 E.Dist Max

AtCoder Beginner Contest 178 E.Dist Max

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If we know a $For\; n$ -dimensional points, if there is an operator for each dimension, it is obvious that there are a total of$2^n$ types of operations, and the Manhattan distance is the difference between the maximum and minimum of the results of these operations, then for this problem, you only need to enumerate all the cases and calculate the maximum difference. The AC code is as follows:

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=2e5+5;
ll a[N][2];
int n;
ll GetManhattan(int n, int dem)
{
    
    
    ll ans=0,Min,Max;
    int i,j,k;
    for(i=0;i<(1<<(dem));i++) {
    
    
        Min=1e18,Max=-1e17;
        for(j=0;j<n;j++){
    
    
            ll sum = 0;
            for(k=0;k<2;k++){
    
    
                if(i&(1<<k)) sum+=a[j][k];
                else sum-=a[j][k];
            }
            if(sum>Max) Max=sum;
            if(sum<Min) Min=sum;
        }
        ans=max(ans,Max-Min);
    }
    return ans;
}

int main() {
    
    
    scanf("%d",&n);
    for(int i=0;i<n;i++)
        for(int j=0;j<2;j++)
            scanf("%lld",&a[i][j]);
    ll ans=GetManhattan(n,2);
    printf("%lld\n", ans);
    return 0;
}