本文共 985 字，大约阅读时间需要 3 分钟。

样例

1    / \   2   4  / \ 2   3

[  [1, 2, 2],  [1, 4]]

解法：DFS，注意路径和的概念，要到叶子节点

AC代码：

class Solution {public:    /*     * @param root: the root of binary tree     * @param target: An integer     * @return: all valid paths     */    vector
   
    
     > binaryTreePathSum(TreeNode * root, int target) {        // write your code here        vector
     
      
       > res;        if(!root){            return res;        }        vector
       
         a;        TreePathSum(root, target, 0, a, res);        return res;    }    void TreePathSum(TreeNode * root, int target,int now, vector
        
         & a, vector
         
          
           > &res) { // write your code here now += root->val; a.push_back(root->val); if(now == target){ if(!root->right && !root->left ) res.push_back(a); } if(root->left){ TreePathSum(root->left, target, now, a, res); a.pop_back(); } if(root->right){ TreePathSum(root->right, target, now, a, res); a.pop_back(); } return ; }};
          
         
        
       
      
     
    
   

转载地址：http://axoli.baihongyu.com/