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알고리즘 문제풀이/leetcode142

[leetcode 94] Binary Tree Inorder Traversal Example 1: Input: root = [1,null,2,3] Output: [1,3,2] Example 2: Input: root = [] Output: [] Example 3: Input: root = [1] Output: [1] 1) recursive 풀이 class Solution { public: void Recursive(TreeNode* root, vector &answer){ if(root == nullptr){ return; } Recursive(root->left, answer); answer.push_back(root->val); Recursive(root->right, answer); } vector inorderTraversal(TreeNode* root) { vector a.. 2020. 10. 4.
[leetcode 102] Binary Tree Level Order Traversal 같은 레벨의 노드끼리 배열을 만들어 return한다. Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example: Given binary tree [3,9,20,null,null,15,7], return its level order traversal as: [ [3], [9,20], [15,7] ] 풀이 - 큐와 bfs를 이용하여 레벨 별로 노드를 저장한다. /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNod.. 2020. 10. 3.
[leetcode 993] Cousins in Binary Tree - 두 노드가 부모가 다르고 같은 depth를 가진 cousin인지 확인하기 In a binary tree, the root node is at depth 0, and children of each depth k node are at depth k+1. Two nodes of a binary tree are cousins if they have the same depth, but have different parents. We are given the root of a binary tree with unique values, and the values x and y of two different nodes in the tree. Return true if and only if the nodes corre.. 2020. 10. 3.
[leetcode 1022] Sum of Root To Leaf Binary Numbers You are given the root of a binary tree where each node has a value 0 or 1. Each root-to-leaf path represents a binary number starting with the most significant bit. For example, if the path is 0 -> 1 -> 1 -> 0 -> 1, then this could represent 01101 in binary, which is 13. For all leaves in the tree, consider the numbers represented by the path from the root to that leaf. Return the sum of these .. 2020. 10. 3.

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