Possible random value generator

randomValue.js

const crypto = require('crypto')


/**
 * Generates an evenly distributed random number.
 * Basically, keep performing rounds until we have one champion. Each round a
 * random number is generated for every remaining character in choices. If the
 * random number is a maximum, those characters go onto the next round, until
 * there is only one maximum left.
 */
function randomValue(characterList) {
    let choices = characterList

    while (choices.length !== 1) {
        let rv = crypto.randomBytes(choices.length)
        let max = 0
        for (let i = 1; i < rv.length; i++) {
            if (rv[i] > rv[max]) {
                max = i
            }
        }
        let choicesNext = ''
        for (let i = 0; i < choices.length; i++) {
            if (rv[i] == rv[max]) {
                choicesNext += choices[i]
            }
        }
        choices = choicesNext
    }

    return choices[0]
}

// Test it out :)
const characterList = '0123456789'

let d = new Map()

for (let i = 0; i < 10000000; i++) {
    rv = randomValue(characterList)
    if (d.has(rv) !== true) {
        d.set(rv, 1)
    } else {
        d.set(rv, d.get(rv) + 1)
    }
}

for (let j = 0; j < characterList.length; j++) {
    const c = characterList[j]
    console.log(`${c}: ${d.get(c)}`)
}