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

int main()

{
    int usr = 1, cpu = 0, result = 0;

    do
    {
        cout << "Let's play rock-paper-scissors. Enter 1 to choose rock, 2 for paper, and 3 for scissors. Enter 0 to quit." << endl;
        cin >> usr;

        switch (usr)
        {
            case 1:
                cout << "You chose rock." << endl;
                break;
            case 2:
                cout << "You chose paper." << endl;
                break;
            case 3:
                cout << "You chose scissors." << endl;
                break;

            default:
                cout << "You done goofed. Input a valid number." << endl;

        }

    }

    while (usr < 0 || usr > 3);

    srand(time(NULL));
    cpu = rand() %3 + 1;

    if (cpu == 1)
    {

    cout << "Computer chose rock." << endl;

        if (usr == 1)
        cout << "It's a tie!" << endl;

        else if (usr == 2)
        cout << "Computer wins!" << endl;

        else
        cout << "You win!" << endl;
    }

    else if ( cpu == 2)
    {

    cout << "Computer chooses paper." << endl;

        if (usr == 1)
        cout << "Computer wins!" << endl;

        else if (usr == 2)
        cout << "It's a tie!" << endl;

        else
        cout << "You win!" << endl;
    }

    else
    {

    cout << "Computer chooses scissors." << endl;
        if (usr == 1)
        cout << "You win!" << endl;

        else if (usr == 2)
        cout << "Computer wins!" << endl;

        else
        cout << "It's a tie!" << endl;
    }

    return 0;
}