Swap Vectors

#include <iostream>
#include <vector>
using namespace std;

int main()
{
vector<int> list_1 (3, 100); // three ints with a value of 100
vector<int> list_2 (5, 200); // five ints with a value of 200

cout << "BEFORE: " << endl;
cout << "list_1 contains: ";
for (unsigned i = 0; i < list_1.size(); i++)
cout << "\t" << list_1[i];

cout << endl << "list_2 contains: ";
for (unsigned i = 0; i < list_2.size(); i++)
cout << "\t" << list_2[i];

list_1.swap(list_2); // swaps values in two different vectors

cout << endl << "AFTER: " << endl;
cout << "list_1 contains: ";
for (unsigned i = 0; i < list_1.size(); i++)
cout << "\t" << list_1[i];

cout << endl << "list_2 contains: ";
for (unsigned i = 0; i < list_2.size(); i++)
cout << "\t" << list_2[i];

swap(list_1, list_2); // swaps the values AGAIN

cout << endl << "AFTER SECOND TIME: " << endl;
cout << "list_1 contains: ";
for (unsigned i = 0; i < list_1.size(); i++)
cout << "\t" << list_1[i];

cout << endl << "list_2 contains: ";
for (unsigned i = 0; i < list_2.size(); i++)
cout << "\t" << list_2[i];

cout << endl << endl;
return 0;
}