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"]
Credits:
Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.
//簡單的二叉樹遍歷,遍歷的過程中記錄之前的路徑,一旦遍歷到葉子節點便將該路徑加入結果中。 class Solution { public: vectorbinaryTreePaths(TreeNode* root) { vector res; if (root==NULL) return res; binaryTreePaths(res, root, to_string(root->val)); return res; } void binaryTreePaths(vector & result, TreeNode* node, string s) { if (node->left==NULL && node->right==NULL) { result.push_back(s); return; } if (node->left) binaryTreePaths(result, node->left, s + "->" + to_string(node->left->val)); if (node->right) binaryTreePaths(result, node->right, s + "->" + to_string(node->right->val)); } };