Given a binary tree, return all root-to-leaf paths.
For example, given the following binary tree:
1
/ \
2 3
\
5
All root-to-leaf paths are: ["1->2->5", "1->3"]
Idea: use to_string function to trans int to string :)
/**
* 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:
vector<string> binaryTreePaths(TreeNode* root) {
vector<string> r = vector<string>();
if(root == NULL){
return r;
}else if(root->left == NULL && root->right == NULL){
string s = string();
r.push_back(s + to_string(root->val));
}else if(root->left == NULL && root->right != NULL){
vector<string> t = binaryTreePaths(root->right);
string s = string();
for(int i=0;i<t.size();i++) r.push_back(s+to_string(root->val) + "->" + t[i]);
}else if(root->left != NULL && root->right == NULL){
vector<string> t = binaryTreePaths(root->left);
string s = string();
for(int i=0;i<t.size();i++) r.push_back(s+to_string(root->val) + "->" + t[i]);
}else{
vector<string> t = binaryTreePaths(root->right);
string s = string();
for(int i=0;i<t.size();i++) r.push_back(s+to_string(root->val) + "->" + t[i]);
t = binaryTreePaths(root->left);
for(int i=0;i<t.size();i++) r.push_back(s+to_string(root->val) + "->" + t[i]);
}
return r;
}
};
