Function sample

packages/procgen/src/random/Shuffle.ts:60–87

(array: readonly T[], count: number, rng: SeededRandom | { next(): number })

 * @returns @zh 采样结果 @en Sample result
 */
export function sample<T>(array: readonly T[], count: number, rng: SeededRandom | { next(): number }): T[] {
    if (count > array.length) {
        throw new Error('Sample count exceeds array length');
    }

    if (count === array.length) {
        return shuffleCopy(array, rng);
    }

    // For small sample sizes relative to array, use selection
    if (count < array.length / 2) {
        const result: T[] = [];
        const indices = new Set<number>();

        while (result.length < count) {
            const index = Math.floor(rng.next() * array.length);
            if (!indices.has(index)) {
                indices.add(index);
                result.push(array[index]);
            }
        }

        return result;
    }

    // For large sample sizes, shuffle and take first N
    return shuffleCopy(array, rng).slice(0, count);
}

/**
 * @zh 从数组中随机采样 N 个元素（可重复）