@extra-array/insertion-sort-update/index.js

'use strict';

/**
 * Compares two values.
 * @param a a value
 * @param b another value
 * @returns a<b: -1, a=b: 0, a>b: 1
 */
function cmp(a, b) {
    return a < b ? -1 : (a > b ? 1 : 0);
}

function insertionSortPair$(x, fc, m) {
    var X = x.length, diff = x !== m;
    for (var i = X - 2; i >= 0; i--) {
        var xv = x[i], mv = m[i];
        for (var j = i + 1; j < X; j++) {
            if (fc(mv, m[j]) <= 0)
                break;
            x[j - 1] = x[j];
            if (diff)
                m[j - 1] = m[j];
        }
        x[j - 1] = xv;
        if (diff)
            m[j - 1] = mv;
    }
    return x;
}
/**
 * Arranges values in an order.
 * @param x an array (updated)
 * @param fc compare function (a, b)
 * @param fm map function (v, i, x)
 * @returns x
 */
function insertionSort$(x, fc = null, fm = null) {
    var fc = fc || cmp;
    if (fm)
        return insertionSortPair$(x, fc, x.map(fm));
    else
        return insertionSortPair$(x, fc, x);
}

module.exports = insertionSort$;