#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

using namespace std;

typedef pair<int, string> data_t;

int main(){
    vector<data_t> data_array(3);

    data_array[0].first = 15;
    data_array[0].second = "zzz";
    data_array[1].first = 30;
    data_array[1].second = "aaa";
    data_array[2].first = 15;
    data_array[2].second = "ccc";


    sort(data_array.begin(), data_array.end());

    for(int i = 0; i < data_array.size(); ++i){
        cout << "i " << i << ": " << endl;
        cout << "  num: " << data_array[i].first << endl;
        cout << "  str: " << data_array[i].second << endl;
    }
    return 0;
}