dfs深搜
/**
* 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:
string tmp;
vector<string> ans;
void dfs(TreeNode* root) {
if(!root->left && !root->right){
ans.push_back(tmp);
return;
}
string k=tmp;
if(root->left) tmp+="->"+to_string(root->left->val),dfs(root->left),tmp=k;
if(root->right) tmp+="->"+to_string(root->right->val),dfs(root->right),tmp=k;
}
vector<string> binaryTreePaths(TreeNode* root) {
if(!root) return ans;
tmp+=to_string(root->val);
dfs(root);
return ans;
}
};