Envío 4958

Código

/// Write by Daniel Perez .PERAPRO
#include<bits/stdc++.h>

using namespace std;
#define fast_io ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define pb push_back
#define ff first
#define ss second
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
using vi=vector<int>;
using vl=vector<ll>;
using pii=pair<int,int>;
char el = '\n';
char esp = ' ';

template<class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }

ostream& operator<<(ostream& os, const vector<int> &v){
    for(auto const &i: v){
        os<<i<<" ";
    }
    os<<'\n';
    return os;
}
string yes="YES";
string no="NO";

const int N=105;

ll mx[N][N];

ll sums[N][N];

ll oo = 1e15;

int main(){
	fast_io;
	/*
 	freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
    */
    int n,m;
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            cin>>mx[i][j];
        }
    }
    
    for(int i=1;i<=n;i++){
        for(int j=1;j<=m;j++){
            sums[i][j] = mx[i][j] + sums[i - 1][j] + sums[i][j - 1] - sums[i - 1][j - 1];
        }
    }
    
    ll ans= - oo;
    
    for(int i=1;i<=n;i++){
        for(int ii=i;ii<=n;ii++){
            for(int j=1;j<=m;j++){
                for(int jj=j;jj<=m;jj++){
                    ckmax(ans, sums[ii][jj] + sums[i - 1][j - 1] - sums[ii][j - 1] - sums[i - 1][jj]);
                }
            }
        }
    }
    
    cout<<ans<<el;
}

/*

*/