题目描述

dfs求解路径

样例

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    vector<vector<int>> res_paths;
    vector<int> path;

    void dfs(TreeNode* root, int sum)
    {
        if(!root)
            return;

        sum -= root->val;
        path.push_back(root->val);
        if(!root->left && !root->right && sum == 0){
            res_paths.push_back(path);
        }
        if(sum > 0)
        {
            dfs(root->left, sum);
            dfs(root->right, sum);
        }
        path.pop_back();
    }
    vector<vector<int>> findPath(TreeNode* root, int sum) {
        dfs(root, sum);
        return res_paths;
    }
};