---
title: "113. Path Sum II"
created: 2025-12-17
---
# 113. Path Sum II

## 题目 [**113. Path Sum II**](https://leetcode.com/problems/path-sum-ii/)

![[image-379ab6ab.png]]

## 思路分析

dfs

## 代码实现

```java
/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    public List<List<Integer>> pathSum(TreeNode root, int targetSum) {
        List<List<Integer>> result = new ArrayList<>();
        List<Integer> path = new ArrayList<>();

        dfs(root,targetSum,path,result);
        return result;
    }

    private void dfs(TreeNode node,int targetSum,List<Integer> path,List<List<Integer>> result){
        if(node == null)    return;

        targetSum-=node.val;
        path.add(node.val);

        if(node.left == null && node.right == null){
            if(targetSum==0){
                result.add(new ArrayList<>(path));
            }
        }else{
            dfs(node.left,targetSum,path,result);
            dfs(node.right,targetSum,path,result);
        }

        targetSum+=node.val;
        path.remove(path.size()-1);
    }
}
```

```java
/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode() {}
 *     TreeNode(int val) { this.val = val; }
 *     TreeNode(int val, TreeNode left, TreeNode right) {
 *         this.val = val;
 *         this.left = left;
 *         this.right = right;
 *     }
 * }
 */
class Solution {
    public List<List<Integer>> pathSum(TreeNode root, int targetSum) {
        List<List<Integer>> result = new ArrayList<>();
        List<Integer> path = new ArrayList<>();

        dfs(root,targetSum,path,result);
        return result;
    }

    private void dfs(TreeNode node,int targetSum,List<Integer> path,List<List<Integer>> result){
        if(node == null)    return;

        path.add(node.val);

        if(node.left == null && node.right == null){
            if(targetSum==node.val){
                result.add(new ArrayList<>(path));
            }
        }else{
            dfs(node.left,targetSum-node.val,path,result);
            dfs(node.right,targetSum-node.val,path,result);
        }

        path.remove(path.size()-1);
    }
}
```

## 同类题型

## 视频讲解