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] ]
/** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: void sub(vector<vector<int> >& ret,vector<int>& val,TreeNode *root,int sum){ // Start typing your C/C++ solution below // DO NOT write int main() function if(root==NULL)return; if(root->left==NULL&&root->right==NULL){ //leaf if(root->val==sum){ val.push_back(root->val); ret.push_back(val); val.pop_back(); } else return; } else{ val.push_back(root->val); sub(ret,val,root->left,sum-root->val); sub(ret,val,root->right,sum-root->val); val.pop_back(); } } vector<vector<int> > pathSum(TreeNode *root, int sum) { // Start typing your C/C++ solution below // DO NOT write int main() function vector<vector<int> > ret; vector<int> val; sub(ret,val,root,sum); return ret; } };