Done is better than perfect

| Question Given two strings s and t, determine if they are isomorphic. Two strings s and t are isomorphic if the characters in s can be replaced to get t. All occurrences of a character must be replaced with another character while preserving the order of characters. No two characters may map to the same character, but a character may map to itself. 번역 : 문자열 s와 t가 주어졌을 때 두 문자열이 isormorphic인지 판단..

Question Given an m x n 2D binary grid [grid] which represents a map of '1's (land) and '0's (water), return the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by water. m x n 인 2차원 grid가 주어진다. grid의 1은 땅, 0은 물을 의미할 때 island의 개수를 세라. island는 물로 상하좌우가 둘러싸인 땅을 의미..

Question Given the root of a binary search tree, and an integer k, return the kth smallest value (1-indexed) of all the values of the nodes in the tree. 이진 탐색 트리와 정수 k가 주어졌을 때, 모든 노드 중 k번째로 작은 값을 리턴하는 함수를 작성하라. 제약사항 The number of nodes in the tree is n. 1 right); } int kthSmallest(TreeNode* root, int k) { vector node_val_vec; AddAllElement(node_val_vec, root); return node_val_vec[k-1]; } }; Time..

Question You are given a perfect binary tree where all leaves are on the same level, and every parent has two children. The binary tree has the following definition: 완전 이진트리가 주어진다면 같은 레벨의 노드를 모두 오른쪽으로 연결하는 함수를 작성하라. struct Node { int val; Node *left; Node *right; Node *next; } Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be s..

Question Given two integer arrays preorder and inorder where preorder is the preorder traversal of a binary tree and inorder is the inorder traversal of the same tree, construct and return the binary tree. 이진 탐색 트리의 preorder 순서와 inorder순서로 탐색한 결과인 두 배열이 주어질 때, 원래의 이진트리를 출력하라. 제약사항 1

Question Given the root of a binary tree, return the zigzag level order traversal of its nodes' values. (i.e., from left to right, then right to left for the next level and alternate between). 이진트리의 root 가 주어졌을 때 지그재그로 노드의 값을 출력하는 함수를 작성하라. 제약사항 The number of nodes in the tree is in the range [0, 2000]. -100 left){ next_level.push(top->left); } if(top->right){ next_level.push(top->right); } }els..

Question Task Scheduler Given a characters array tasks, representing the tasks a CPU needs to do, where each letter represents a different task. Tasks could be done in any order. Each task is done in one unit of time. For each unit of time, the CPU could complete either one task or just be idle. char type의 원소로 이루어진 task배열이 주어진다. 배열의 각 task들은 CPU가 해야 하는 일이며, 각각의 letter는 각기 다른 task들을 나타낸다. Task 들은..

Question Majority Element Given an array nums of size n, return the majority element. The majority element is the element that appears more than ⌊n / 2⌋ times. You may assume that the majority element always exists in the array. size가 n인 배열이 주어질 때, majority 한 원소를 return 하라. majority 한 원소란, 전체 배열에서 n/2 이상 등장한 원소를 뜻한다. 배열 안에 majority 원소가 항상 있다고 생각해도 좋다. 제약사항 n == nums.length 1