Сравнение элементов вектора

#include "std_lib_facilities.h"
using namespace std;
int main()
{
    vector<int> numbers;
    int figure = 0;
    int i = 0;
    cout << "Input two separated figures: " << endl;
    while (cin >> figure)
        numbers.push_back(figure);
    cout << "The least value of two is: " << endl;
    sort(numbers.begin(), numbers.end());
    for (i = 0; i < numbers.size(); ++i)
        cout << numbers[i] << endl;
    return EXIT_SUCCESS;
}

if (i = 0, numbers[] = numbers[i], ++i) cout << "The equal numbers is: " << numbers[] << endl;

if (i = 0, numbers[] = numbers[i], ++i) cout << "The equal numbers is: " << numbers[] << endl;

#include "std_lib_facilities.h"
using namespace std;
int main()
{
    vector<pair<int,int>> numbers;
    int figure1,figure2;
    int i = 0;
    cout << "Input two separated figures: " << endl;
    while (cin >> figure1 >> figure2)
        numbers.push_back(make_pair(figure1,figure2));
    cout << "The least value of two is: " << endl;
    sort(numbers.begin(), numbers.end());
    for (i = 0; i < numbers.size(); ++i)
        if( numbers[i].first == numbers[i].second )
            cout << numbers[i].first << endl;
    return EXIT_SUCCESS;
}

if (i = 0, numbers[] = numbers[i], ++i) cout << "The equal numbers is: " << numbers[] << endl;