operator-overloading.cpp

#include <cmath>
#include <vector>
#include <iostream>

using namespace std;

class Matrix {
public:
    vector<vector<int> > a;

    Matrix & operator + (const Matrix &y) {
        for (int m=0; m<y.a.size(); ++m) {
            for (int n=0; n<y.a[0].size(); ++n) {
                this->a[m][n] = this->a[m][n] + y.a[m][n];
            }
        }
        return *this;
    }
};

int main () {
    int cases,k;
    cin >> cases;
    for(k=0;k<cases;k++) {
        Matrix x;
        Matrix y;
        Matrix result;
        int n,m,i,j;
        cin >> n >> m;
        for(i=0;i<n;i++) {
            vector<int> b;
            int num;
            for(j=0;j<m;j++) {
                cin >> num;
                b.push_back(num);
            }
            x.a.push_back(b);
        }
        for(i=0;i<n;i++) {
            vector<int> b;
            int num;
            for(j=0;j<m;j++) {
                cin >> num;
                b.push_back(num);
            }
            y.a.push_back(b);
        }
        result = x+y;
        for(i=0;i<n;i++) {
            for(j=0;j<m;j++) {
                cout << result.a[i][j] << " ";
            }
            cout << endl;
        }
    }
    return 0;
}