zadatak jabuke (matrica)

#include <iostream>
#include <vector>

using namespace std;

vector< vector<int> > vec;

void _draw() {
    for (int i = 0; i < vec.size(); ++i) {
        for (int i2 = 0; i2 < vec.at(i).size(); ++i2)
            cout << vec.at(i).at(i2) << " ";
        cout << endl;
    }

}

int main() {
    int a, temp1;
    cin >> a;
    for (int i = 0; i < a; ++i) {
        vector<int> temp;
        for (int i2 = 0; i2 < a; ++i2) {
            cin >> temp1;
            temp.push_back(temp1);
        }
        vec.push_back(temp);
    }

    for (int i = 1; i < a; ++i)
        vec.at(i).at(0) += vec.at(i-1).at(0);
    for (int i = 1; i < a; ++i)
        vec.at(0).at(i) += vec.at(0).at(i-1);

    for (int i = 1; i < a; ++i) {
        for (int i2 = 1; i2 < a; ++i2) {
            if (vec.at(i).at(i2-1) > vec.at(i-1).at(i2))
                vec.at(i).at(i2) += vec.at(i).at(i2-1);
            else
                vec.at(i).at(i2) += vec.at(i-1).at(i2);
        }
    }

    cout << vec.at(a-1).at(a-1) << endl;

    string s = "";
    cout << endl;
    //_draw();
    int x = a-1, y = a-1;

    while (x && y) {
        if (vec.at(x).at(y-1) > vec.at(x-1).at(y)) {
            y--;
            //cout << "Down." << endl;
            s = "R" + s;
        }
        else {
            x--;
            //cout << "Right." << endl;
            s = "D" + s;
        }
    }
    s = string(x, 'D') + s;
    s = string(y, 'R') + s;
    cout << s;



    return 0;
}