carita triste

#include <iostream>
#include <vector>
using namespace std;

int n;
vector< vector<int> > m;
vector< vector<int> > DP;

int main ()
{
    cin>>n;
    m = vector< vector<int> > (n, vector<int> (n));
    DP = vector< vector<int> > (n+1, vector<int> (n+1, 0) );

    for (int i=0; i<n; i++)
    {
        for(int j=0; j<n; j++)
        {
            cin>>m[i][j];
        }
    }
    cout<<endl<<endl;
    for (int i=0; i<n; i++)
        for(int j=0; j<n; j++)
            DP[i+1][j+1] = m[i][j] + DP[i+1][j] + DP[i][j+1] - DP[i][j];

    for (int i=0; i<=n; i++)
    {
        cout<<endl;
        for(int j=0; j<=n; j++)
        {
            cout<<DP[i][j]<<" ";
        }
    }

    int x1=3, y1=2, x2=1, y2=1;

    cout<<DP[x1][y1]...;

    return 0;
}