剑指 Offer 34. 二叉树中和为某一值的路径 || LeetCode 113. 路径总和 II

绝地灬酷狼 2022-11-05 03:17 118阅读 0赞

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zODE5OTc3MA_size_16_color_FFFFFF_t_70]  
[大佬][Link 1]

//众所周知，叶子节点是左右都为null doge
    /**
     * Definition for a binary tree node.
     * public class TreeNode {
     *     int val;
     *     TreeNode left;
     *     TreeNode right;
     *     TreeNode(int x) { val = x; }
     * }
     */
    class Solution {
        
        List<List<Integer>> res = new ArrayList<List<Integer>>();
        List<Integer> tmp = new ArrayList<Integer>();
        public List<List<Integer>> pathSum(TreeNode root, int sum) {
        
            if(root == null)
                return res;
            dfs(root, sum);
            return res;
        }
        private void dfs(TreeNode root, int sum){
        
            if(root == null)
                return;
            tmp.add(root.val);
            sum -= root.val;
            if(sum == 0 && root.left == null && root.right == null)
                res.add(new ArrayList<>(tmp));
            dfs(root.left, sum);
            dfs(root.right, sum);
            tmp.remove(tmp.size() - 1);
        }
    }

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zODE5OTc3MA_size_16_color_FFFFFF_t_70]: /images/20221023/efc9eeae667b445cb6b0154aad765fe5.png
[Link 1]: https://leetcode-cn.com/problems/er-cha-shu-zhong-he-wei-mou-yi-zhi-de-lu-jing-lcof/solution/mian-shi-ti-34-er-cha-shu-zhong-he-wei-mou-yi-zh-5/