LeetCode--Path Sum II

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

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

return

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

/**
 * Definition for binary tree
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution 
{
public:
    vector<vector<int> > pathSum(TreeNode *root, int sum) 
    {
        vector<vector<int>> res;
        vector<int> temp;
        if(root == NULL)
            return res;
        pathSum(root,sum,0,temp,res);
        return res;
    }
    void pathSum(TreeNode *root, int sum, int now, vector<int>& temp, vector<vector<int>>& res) 
    {
        if(root == NULL)
            return;
        if(root->left ==NULL && root->right == NULL)
        {
            if(sum == now+root->val)
            {
                temp.push_back(root->val);
                res.push_back(temp);
                temp.pop_back();
            }
            return;
        }
        temp.push_back(root->val);
        if(root->left != NULL)
            pathSum(root->left,sum,now+root->val,temp,res);
        if(root->right!=NULL)
            pathSum(root->right,sum,now+root->val,temp,res);
        temp.pop_back();
        return ;
    }
};

LeetCode--Path Sum II

原文：http://blog.csdn.net/shaya118/article/details/42711183