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@EXayer
Created October 9, 2020 13:31
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The Monty Hall Problem - brute force proof
const CHANCE = 3;
function rollDoor() {
return Math.floor(Math.random() * CHANCE);
}
function randArr(arr) {
return arr[Math.floor(Math.random() * arr.length)];
}
function removeRandom(arr, hidden, choosen) {
if (hidden !== choosen) {
return [arr[hidden], arr[choosen]];
}
const variants = [];
for (let i = 0; i < arr.length; i++) {
if (hidden === i || choosen === i) {
continue;
}
variants.push(arr[i]);
}
return [arr[hidden], randArr(variants)];
}
function game(do_choose = false, times = 100000) {
const stat = {
'count': times,
'win': 0,
'lose': 0
};
for (let i = 0; i < times; i++) {
const variants = [1, 2, 3];
const hidden = rollDoor();
const choosen = rollDoor();
// remove 1 door
const variants2 = removeRandom(variants, hidden, choosen);
if (do_choose) {
let new_choosen = -1;
for (let i = 0; i <= variants2.length; i++) {
if (variants[choosen] !== variants2[i]) {
new_choosen = variants2[i];
break;
}
}
if (variants[hidden] === new_choosen) {
stat['win']++;
} else {
stat['lose']++;
}
continue;
}
if (choosen === hidden) {
stat['win']++;
} else {
stat['lose']++;
}
}
return stat;
}
const stat = game();
console.log('------ No Change -------');
console.log(`Count: ${stat['count']}, Win: ${stat['win']}, Lose: ${stat['lose']}`);
const stat2 = game(true);
console.log('------- New Door -------');
console.log(`Count: ${stat2['count']}, Win: ${stat2['win']}, Lose: ${stat2['lose']}`);
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