dev-chee

// 排列算法 P_{cnt}^{nums.len()}
fn permutation(nums: Vec<i32>, cnt: usize) -> Vec<Vec<i32>> {
    fn helper(result: &mut Vec<Vec<i32>>, nums: &mut Vec<i32>, cnt: usize, idx: usize) {
        if idx == cnt {
            result.push(Vec::from(&nums[..idx]));
            return;
        }

        // 第idx个元素可选择的方法
        for i in idx..nums.len() {

dev-chee

using System;

namespace hello_csharp
{
    class Program
    {
        class Node
        {
            public int val;
            public Node next;