Official RNF Test of Intelligence

[Recycled Children]

Originally Posted by Hasbinbad [You must be logged in to view images. Log in or Register.]

lol ur old.

Says the 35 year old.

[r00t]

I wrote a program after reading a lot of mathematicians were only convinced after seeing computer simulations. In 9000 trials, switching makes you win ~6000 (2/3), not switching only ~3000 (1/3)

#include <stdio.h>
#include <stdlib.h>

#define MONTY_TRIALS 9000

bool monty_hall_problem(bool switch_doors)
{
    bool doors[3] = { false, false, false };
    doors[rand()%3] = true;

    unsigned int choice = rand() % 3;
    return (switch_doors) ? !doors[choice] : doors[choice];
}

int main(int argc, char* argv[])
{
    int switch_wins = 0, no_switch_wins = 0;

    for (int i = 0; i < MONTY_TRIALS; ++i)
    {
        if (monty_hall_problem(true)) ++switch_wins;
        if (monty_hall_problem(false)) ++no_switch_wins;
    }

    printf("Switch: %d\tNo Switch: %d", switch_wins, no_switch_wins);

    return 0;
}

[r00t]

I forgot to seed rand there but then I did and the same shit happens anyway DUh

[Systolic]

Monty Hall question.

Variable change. Always take the switch. You get an additional 17% equity.

[Lune]

You all done fucked up my thread with your slightly higher than average level of knowledge/intelligence/age.

This works much better elsewhere on the internet.

[Tecmos Deception]

Originally Posted by Lune [You must be logged in to view images. Log in or Register.]

You all done fucked up my thread with your slightly higher than average level of knowledge/intelligence/age.

This works much better elsewhere on the internet.

It's so funny how many people refused to believe this for so long. It doesn't help an average Joe that so many of the explanations are kinda roundabout and confusing ways of explaining it though, imo.

What's better, people? A 50% chance of picking the right bag, or a 33% chance of picking the right bag? When you make your first pick, you're only getting the 33% chance of being correct. After Tunare reveals an empty bag though, you can either stick with your 33% chance original choice or switch to the 50% chance bag. Derp.

[ncapatina]

It's amazing how many people refuse to believe that switching improves your odds.

I remember a day at work about 3-4 years ago where a co-worker (a very solid network engineer, not a dude flipping burgers) and I got into a heated discussion about it. He just wouldn't believe it so I made it easy on him and I'll do it for the retards here.

Play out each scenario with the prize being in bag #2. Keep in mind that when Tunare in this case reveals a second bag, it CANNOT be the winning bag. So if you've picked bag 1, bag 3 will be revealed 100% of the time. If you pick bag 3 it will be bag one revealed 100% of the time. If you pick bag 2, it could be either.

You pick bag one and keep it = lose.
You pick bag two and keep it = win.
You pick bag three and keep it = lose.

You pick bag one and switch to bag two = win.
You pick bag one and switch to bag three = cannot be done, revealed as a loser.
You pick bag two and switch to bag one = lose.
You pick bag two and switch to bag three = lose.
You pick bag three and switch to bag one = cannot be done, revealed as a loser.
You pick bag three and switch to bag two = win.

So you can very simply look at this and say, if I stay I have a 1 in 3 chance (33%), if I switch I have a 2 in 4 chance (50%).

Switch every time. Like was stated above, you improve your odds 17%.

[ncapatina]

Oh, and also this:

http://en.wikipedia.org/wiki/Monty_Hall_problem

[DrKvothe]

It doubles your chance of being right, actually.

If you switch, the only way you lose is if your initial choice was correct, which was a 33% chance. That means you win 66% of the time when you switch.

[Hasbinbad]

MATH HURTS MAI BRAIN LAL