LeetCode 0113 - Path Sum II

Path Sum II

Desicription

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,

代码语言：javascript复制

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

return

代码语言：javascript复制

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

Solution

代码语言：javascript复制

/**
 * 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 {
private:
    vector<vector<int>> res;
    void searchTree(TreeNode* root, int sum, const int& target, vector<int> vec) {
        if(root == NULL)
            return ;
        vec.push_back(root->val);
        if(root->left == NULL && root->right == NULL)
            if(sum   root->val == target)
                res.push_back(vec);
        searchTree(root->left, sum   root->val, target, vec);
        searchTree(root->right, sum   root->val, target, vec);
    }
public:
    vector<vector<int>> pathSum(TreeNode* root, int sum) {
        if(root == NULL)
            return res;
        searchTree(root, 0, sum, vector<int>());
        return res;
    }
};

binary equals root sum tree

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