computational-combinatorics/permutation

import {_transpose} from './_transpose.js';

/**
 * Reverses input permutation ___in-place___ from input index <code>i</code>
 * (include) to input index <code>j</code> (excluded).
 *
 * @param {Array} sigma The input permutation to reverse (modified in-place).
 * @param {number} i The left bound (included).
 * @param {number} j The right bound (excluded).
 */
export function _reverse(sigma, i, j) {
    while (i < --j) _transpose(i++, j, sigma);
}