CODEWITHSUNDEEP
c++vectoriteratorsetstd-pair
adam_
adam_

Reputation: 25

C++ iterators for set & pair

I got some problems how to define & use iterators.

This is an ilustration of my code.

set< pair<int, pair<int,int> > > data1;
set< pair<int , pair<int,int> > > iterator it1;
// imagine set < pair x , pair < y , z >>>

vector<set <int> > data2;
set<int>::iterator it2;

vector< pair<int,int> > data3;
vector< pair<int,int> > it3;

How can I display content of data1,data2,data3 with iterators please ? Thanks for any help.

Upvotes: 1

Views: 651

Answers (1)

Bill Lynch
Bill Lynch

Reputation: 81936

It's fairly straightforward...

#include <iostream>
#include <set>
#include <utility>
#include <vector>

int main() {
    std::set<std::pair<int, std::pair<int,int>>> data1;
    data1.emplace(3, std::make_pair(4, 5));
    data1.emplace(6, std::make_pair(7, 8));

    for (auto p : data1)
        std::cout << std::get<0>(p) << " " << std::get<0>(std::get<1>(p)) << " " << std::get<1>(std::get<1>(p)) << "\n";
    std::cout << "\n";

    std::vector<std::set<int>> data2;
    data2.push_back({4,5,6});
    data2.push_back({7,8,9});

    for (auto set_element : data2) {
        for (auto element : set_element)
            std::cout << element << " ";
        std::cout << "\n";
    }
    std::cout << "\n";

    std::vector<std::pair<int,int>> data3;
    data3.emplace_back(1, 2);
    data3.emplace_back(3, 4);

    for (auto p : data3)
        std::cout << std::get<0>(p) << " " << std::get<1>(p) << "\n";
    std::cout << "\n";
}

Which outputs...

3 4 5
6 7 8

4 5 6 
7 8 9 

1 2
3 4

Upvotes: 1

Related Questions