力扣-二叉树-257 二叉树的所有路径

思路

除去根节点，每一层添加->val，然后使用前序遍历的顺序

代码

class Solution {
public:vector<string> res;void getTreePaths(string s, TreeNode* root){s += "->";s += to_string(root->val);if(root->left == nullptr && root->right == nullptr){res.push_back(s);return;}if(root->left) getTreePaths(s, root->left);if(root->right) getTreePaths(s, root->right);}vector<string> binaryTreePaths(TreeNode* root) {if(root->left == nullptr && root->right == nullptr){res.push_back(to_string(root->val));return res;}string s;if(root->left) getTreePaths(to_string(root->val), root->left);if(root->right) getTreePaths(to_string(root->val), root->right);return res;}
};