Day37_ [LeetCode简单] 113. 路径总和 II

Day37: [LeetCode简单] 113. 路径总和 II

题源：

来自leetcode题库：

https://leetcode-cn.com/problems/path-sum-ii/

代码：

dirty code凑合看吧

/**
 * 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:
    int Sum;
    vector<vector<int> > res;
    vector<int> f(TreeNode* root,int sum){
        vector<int> re;
        if(root){
            if(root->left==NULL&&root->right==NULL){
                if(sum+root->val==Sum) {
                    vector<int> v;
                    v.push_back(root->val);
                    res.push_back(v);
                    re.push_back(res.size()-1);
                    return re;
                }
                else return re;
            } else{
                auto x=f(root->left,sum+root->val),y=f(root->right,sum+root->val);
                for(auto i:x){
                    res[i].push_back(root->val);
                    re.push_back(i);
                }
                for(auto i:y){
                    res[i].push_back(root->val);
                    re.push_back(i);
                }
                return re;
            }
        }else return re;
    }
    vector<vector<int>> pathSum(TreeNode* root, int sum) {
        if(!root) return res;
        Sum=sum;
        f(root,0);
        for(int i=0;i<res.size();i++){
            reverse(res[i].begin(),res[i].end());
        }
        //reverse(res[0].begin(),res[0].end());
        return res;
    }
};