integer-partition.js

function* zs1(n) {
    "use strict";

    if (n <= 0) throw new Error('positive integer only');
    yield [n];

    var x = new Array(n);
    x[0] = n;
    for (var i = 1; i < n; i++) x[i] = 1;

    var m = 0, h = 0, r, t;
    while (x[0] != 1) {
        if (x[h] == 2) {
            m += 1;
            x[h] = 1;
            h -= 1;
        } else {
            r = x[h] - 1;
            x[h] = r;

            t = m - h + 1;
            while (t >= r) {
                h += 1;
                x[h] = r;
                t -= r;
            }
            m = h + (t !== 0 ? 1 : 0);
            if (t > 1) {
                h += 1;
                x[h] = t;
            }
        }
        yield x.slice(0, m + 1);
    }
}

function* zs2(n) {
    "use strict";

    if (n <= 0) throw new Error('positive integer only');

    var x = new Array(n + 1);
    for (var i = 1; i < n + 1; i++) x[i] = 1;
    yield x.slice(1, n + 1);

    x[0] = -1;
    x[1] = 2;
    var h = 1, m = n - 1, j, r;
    yield x.slice(1, m + 1);

    while (x[1] != n) {
        if (m - h > 1) {
            h += 1;
            x[h] = 2;
            m -= 1;
        } else {
            j = m - 2;
            while (x[j] == x[m - 1]) {
                x[j] = 1;
                j -= 1;
            }
            h = j + 1
            x[h] = x[m - 1] + 1;
            r = x[m] + x[m - 1] * (m - h - 1);
            x[m] = 1;
            if (m - h > 1) {
                x[m - 1] = 1;
            }
            m = h + r - 1;
        }
        yield x.slice(1, m + 1);
    }
}

module.exports = {
    zs1: zs1,
    zs2: zs2
}

usage.js

var IntegerPartition = require('integer-partition');

for (var arr of IntegerPartition.zs1(8)) {
    console.log(arr);
}

for (var arr of IntegerPartition.zs2(8)) {
    console.log(arr);
}