标签：style blog color io for ar div 代码
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] ]
分析：此题可以用DFS解，当遍历到叶节点时，判断当前path的sum是否等于target sum，如果相等便将当前path加入到result中。
代码如下：
1 class Solution { 2 public: 3 vector<vector<int> > pathSum(TreeNode *root, int sum) { 4 vector<vector<int>> res; 5 if(!root) return res; 6 vector<int> path; 7 dfs(res,path,root,0,sum); 8 return res; 9 } 10 void dfs(vector<vector<int>> & res, vector<int> & path,TreeNode * root, int pre_sum, int sum){ 11 if(!root) return; 12 path.push_back(root->val); 13 int cur_sum = pre_sum + root->val; 14 dfs(res,path,root->left,cur_sum,sum); 15 dfs(res,path,root->right,cur_sum,sum); 16 if(cur_sum == sum && !root->left && !root->right) res.push_back(path); 17 path.pop_back(); 18 } 19 };
标签：style blog color io for ar div 代码
原文地址：http://www.cnblogs.com/Kai-Xing/p/3909929.html
