es-next-tools/dist/math/comb.js

A comprehensive utility library for JavaScript and TypeScript that provides a wide range of functions for common programming tasks, including mathematical operations, date manipulations, array and object handling, string utilities, and more.

import { factorial } from "./factorial";
/**
 * Calculates the number of combinations (n choose k).
 * @param {number} n - The total number of items.
 * @param {number} k - The number of items to choose.
 * @returns The number of possible combinations.
 * @example
 * ```js
 * comb(5, 3); // 10
 * ```
 */
export function comb(n, k) {
    if (k > n)
        return 0;
    return factorial(n) / (factorial(k) * factorial(n - k));
}