montyhall.cpp

//  Lab #8
//  Created by Atharva Vaidya on 02/29/16.
//  Copyright © 2015 Atharva Vaidya. All rights reserved.

#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <time.h>
#include <cmath>

using namespace std;

int randInRange(int n)
{
    double x = ( double(n) * (double)rand() / ((double) RAND_MAX + 1));
    return int(x);
}

void setupDoors(char &door1, char &door2, char &door3)
{
    
    randInRange(1000);
    
    int doorForCar = randInRange(3);
    
    switch (doorForCar) {
        case 0:
            door1 = 'C';
            door2 = 'G';
            door3 = 'G';
            break;
            
        case 1:
            door1 = 'G';
            door2 = 'C';
            door3 = 'G';
            break;
        case 2:
            door1 = 'G';
            door2 = 'G';
            door3 = 'C';
            break;
            
        default:
            break;
    }
}

void pickDoorChoices(char door1, char door2, char door3, int &doorPlayer, int &doorMonty)
{
    char doors[] = {door1, door2, door3};
    doorPlayer = randInRange(3) + 1;
    
    do
    {
        doorMonty = randInRange(3) + 1;
    }
    while (doorMonty == doorPlayer || doors[doorMonty] == 'C');
    
    
}


int main(void)
{
    int seed = static_cast<int>(time(0));
    
    srand(seed);
    
    char d1, d2, d3;
    
    char doors[] = {d1, d2, d3};
    int doorPlayer = 0, doorMonty, switchToWin = 0, dontSwitchToWin = 0;
    for (int i = 0; i < 100; i++)
    {
        
        
        for (int i = 0; i < 100000; i++)
        {
            setupDoors(d1, d2, d3);
            pickDoorChoices(d1, d2, d3, doorPlayer, doorMonty);
            
            (doors[doorPlayer] == 'C') ? dontSwitchToWin++ : switchToWin++;
            
        }
        
        cout << setprecision(3) << fixed;
        
        cout << double(dontSwitchToWin) * 100 / double(dontSwitchToWin + switchToWin) << "% | " << double(switchToWin) * 100 / double(dontSwitchToWin + switchToWin) << "%" << endl;
    }
    
    
}