437. Path Sum III
2018-03-21 11:07
357 查看
You are given a binary tree in which each node contains an integer value.
Find the number of paths that sum to a given value.
The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to child nodes).
The tree has no more than 1,000 nodes and the values are in the range -1,000,000 to 1,000,000.
Example:
Find the number of paths that sum to a given value.
The path does not need to start or end at the root or a leaf, but it must go downwards (traveling only from parent nodes to child nodes).
The tree has no more than 1,000 nodes and the values are in the range -1,000,000 to 1,000,000.
Example:
root = [10,5,-3,3,2,null,11,3,-2,null,1], sum = 8 10 / \ 5 -3 / \ \ 3 2 11 / \ \ 3 -2 1 Return 3. The paths that sum to 8 are: 1. 5 -> 3 2. 5 -> 2 -> 1 3. -3 -> 11
/** * 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 pathSum(TreeNode* root, int sum) { if(!root) return 0; return dfs(root,sum)+pathSum(root->left,sum)+pathSum(root->right,sum); } int dfs(TreeNode *root ,int sum) { int res=0; if(!root) return res; if(root->val==sum) res++; res +=dfs(root->left,sum-root->val); res +=dfs(root->right,sum-root->val); return res; } };
相关文章推荐
- 437_Path_Sum_III
- 437. Path Sum III
- 437. Path Sum III
- LeetCode 437 Path Sum III (DFS)
- [437]. Path Sum III,[687]. Longest Univalue Path
- leetcode-437-Path Sum III
- 437. Path Sum III
- leetcode(437):Path Sum III
- LeetCode "437. Path Sum III"
- 437. Path Sum III
- 437. Path Sum III
- 437. Path Sum III
- 437. Path Sum III
- 437. Path Sum III
- 437. Path Sum III
- 437. Path Sum III
- LeetCode.112(113/437) Path Sum I && II && III
- 437. Path Sum III
- 437. Path Sum III
- Leetcode算法学习日志-437 Path Sum III