cambiandose_de_aula.cpp

#include <bits/stdc++.h>

using namespace std;

int main(){
    int t; cin>>t;
    while(t--){
        int n,m;
        cin>>n>>m;
        vector<vector<int> > mat(n, vector<int>(m));
        for(auto & fila : mat){
            for(auto & elem : fila){
                cin>>elem;
            }
        }
        vector<vector<int> > dpmax(n, vector<int>(m,-1e9));
        vector<vector<int> > dpmin(n, vector<int>(m,1e9));
        dpmax[0][0] = dpmin[0][0] = mat[0][0];
        for(int i = 0; i <n;i++) for(int j = 0;j<m;j++){
            if(i==0 and j==0) continue;
            if(i>0){
                dpmax[i][j] = max(dpmax[i][j], dpmax[i-1][j] + mat[i][j]);
                dpmin[i][j] = min(dpmin[i][j], dpmin[i-1][j] + mat[i][j]);
            }
            if(j>0){
                dpmax[i][j] = max(dpmax[i][j], dpmax[i][j-1] + mat[i][j]);
                dpmin[i][j] = min(dpmin[i][j], dpmin[i][j-1] + mat[i][j]);
            }
        }
        
        if((n+m)%2==1 and dpmax[n-1][m-1] >=0 and dpmin[n-1][m-1]<=0){
            cout<<"YES"<<endl;
        }else{
            cout<<"NO"<<endl;
        }
    }
}