---
title: "46. Permutations"
created: 2025-12-16
---
# 46. Permutations

## 题目 [**46. Permutations**](https://leetcode.com/problems/permutations/)

![[image-08f244d8.png]]

## 思路分析

c++中有全排列函数`next_permutation` java没有 只能用dfs写

## 代码实现

```java
class Solution {
    List<List<Integer>> res = new ArrayList<>();
    List<Integer> path = new ArrayList<>();
    boolean[] st;

    public List<List<Integer>> permute(int[] nums) {
        int n = nums.length;
        st = new boolean[n];
        
        dfs(nums,0);
        return res;
    }

    void dfs(int[] nums,int u){
        if(u==nums.length){
            res.add(new ArrayList<>(path));
            return;
        }

        for(int i=0;i<nums.length;i++){
            if(!st[i]){
                st[i]=true;
                path.add(nums[i]);

                dfs(nums,u+1);

                path.remove(path.size()-1);
                st[i]=false;
            }
        }
    }
}
```

## 同类题型

## 视频讲解