probability riddle simulation

// install nodejs
// npm seedrandom
// node prog.js

var seedrandom = require('seedrandom');

var map = {};
var sums = {};

var M = 100;

rng = seedrandom();
for (i = 0; i < 10000000; i++) {
    var n = Math.floor((rng() * M) + 1);
    var x = Math.floor((rng() * n) + 1);

    if (!(x in map)) {
        map[x] = {};
    }

    if (!(n in map[x])) {
        map[x][n] = 0;
    }

    if (!(x in sums)) {
        sums[x] = 0;
    }


    map[x][n] += 1;
    sums[x] += 1;

    if (i % 1000000 == 0) {
        console.log("calculating...");
    }
}

for (var x = 1; x <= M; x++) {
    console.log("x = " + x + ": ratio (n=x): " + map[x][x] * 1.0 / sums[x]
        + " ratio (n=x+1): " + map[x][x+1] * 1.0 / sums[x] + " ratio (n=x+2): " + map[x][x+2] * 1.0 / sums[x]);
}