题解 | #二叉树根节点到叶子节点的所有路径和#

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 * };
 */

#include <vector>
class Solution {
public:
    /**
     * 
     * @param root TreeNode类 
     * @return int整型
     */
    vector<vector<int>> v_v;
    vector<int> v;
    void dfs(TreeNode* root)
    {
        if(!root)
        {
            return;
        }

        v.emplace_back(root->val);

        if(!root->left && !root->right)
        {
            v_v.emplace_back(v);
            return;
        }

        if(root->left)
        {
            dfs(root->left);
            v.pop_back();
        }
            
        if(root->right)
        {
            dfs(root->right);
            v.pop_back();
        }

        return;
    }

    int sumNumbers(TreeNode* root) {
        // write code here
        dfs(root);

        int ans=0;
        for(auto temp_v_v:v_v)
        {
            int temp = 0;
            for(auto temp_v:temp_v_v)
            {
                temp = temp*10 + temp_v;
            }

            ans += temp;
        }

        return ans;
    }
};