LeetCode257-二叉树的所有路径-递归-数据结构-深搜

原题链接

class Solution {
public:
    vector ans;

    vector binaryTreePaths(TreeNode* root) {
        dfs(root, "");
        return ans;
    }

    void dfs(TreeNode* root, string path){
        if(!root)   return;
        path += to_string(root -> val) + "->";
        if(!root -> left && !root -> right){
            path.pop_back();
            path.pop_back();
            ans.push_back(path);
            return;
        }
        dfs(root -> left, path);
        dfs(root -> right, path);
        
    }
};