Path Sum II

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Given a binary tree and a sum, find all root-to-leaf paths where each path‘s sum equals the given sum.

For example:
Given the below binary tree and sum = 22,

              5             /             4   8           /   /           11  13  4         /  \    /         7    2  5   1

return

[   [5,4,11,2],   [5,8,4,5]]

 1 /**  2  * Definition for binary tree  3  * struct TreeNode {  4  *     int val;  5  *     TreeNode *left;  6  *     TreeNode *right;  7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}  8  * };  9  */  10 class Solution {  11 public:  12     vector<vector<int> > pathSum(TreeNode *root, int sum) {  13           14         vector<vector<int> > gather;  15         vector<int> rootLeaf;  16         int tempSum = 0;  17         pathSum(root, tempSum, sum, gather, rootLeaf);  18         return gather;  19     }  20       21     void pathSum(TreeNode *root, int tempSum, int sum, vector<vector<int> > &gather, vector<int> rootLeaf)  22     {  23         if(root != NULL)  24         {  25             if(root->left == NULL && root->right == NULL)  26             {  27                 tempSum += root->val;  28                 rootLeaf.push_back(root->val);  29                 if(tempSum == sum)  30                     gather.push_back(rootLeaf);  31                   32                 return;  33             }  34           35             else  36             {  37                 tempSum += root->val;  38                 rootLeaf.push_back(root->val);  39                 pathSum(root->left, tempSum, sum, gather, rootLeaf);  40                 pathSum(root->right, tempSum, sum, gather, rootLeaf);  41             }  42         }  43     }  44 };  

 

Path Sum II