Python으로 공부하는 코딩테스트
1.[Programmers] Level 1 - 크레인 인형 뽑기
어떻게 풀었나? 1-1. board 배열의 행과 열을 바꾼다. > #### 💡 2차원 배열 행과 열 바꾸는 방법 💭 왜? WHY? board 은 인형뽑기 기계의 형태 그대로 표현된 2차원 배열이다. 즉, 인형뽑기 기계의 맨 위의 첫 번째 줄이 board의
2.[Programmers] Level 1 - [1차] 비밀지도
어떻게 풀었나? 💭 코드 개선해볼 수 있을까? 1. 비밀지도 해독 문자열 합치기 방법 개선 문자열을 합치는 방법에는 두 가지가 있다. 문자열을 더해나가는 방법 list에 넣은 다음, string.join()을 통해 마지막에 처리하는 방법 내가 기존에 사용한 방법
3.[Programmers] Level 1 - 숫자 문자열과 영단어
💡 새로 알게 된 내용 1. replace 함수 **str.replace(old, new[, count])** Return a copy of the string with all occurrences of substring old replaced by new. If
4.[Leetcode] Array - Two Sum
Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.You may assume that each inpu
5.[Leetcode] 169. 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 th
6.[Leetcode] 350. Intersection of Two Arrays II
Given two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must appear as many times as it shows in b
7.[Leetcode] 283. Move Zeroes
Given an integer array nums, move all 0's to the end of it while maintaining the relative order of the non-zero elements.Note that you must do this in
8.[Leetcode]167. Two Sum II - Input Array Is Sorted
Given a 1-indexed array of integers numbers that is already sorted in non-decreasing order, find two numbers such that they add up to a specific targe
9.[Leetcode]344. Reverse String
Write a function that reverses a string. The input string is given as an array of characters s.You must do this by modifying the input array in-place
10.[Leetcode]852. Peak Index in a Mountain Array
Let's call an array arr a mountain if the following properties hold:arr.length >= 3There exists some i with 0 < i < arr.length - 1 such that:arr
11.[Leetcode]876. Middle of the Linked List
Given the head of a singly linked list, return the middle node of the linked list.If there are two middle nodes, return the second middle node.Time Co
12.[Leetcode]19. Remove Nth Node From End of List
Given the head of a linked list, remove the nth node from the end of the list and return its head.get the size of the linked list to caculate times fo
13.[Leetcode]3. Longest Substring Without Repeating Characters
Given a string s, find the length of the longest substring without repeating characters.(case1) Don't need to check substrings ❕ If the string is em
14.[Leetcode]733. Flood Fill
An image is represented by an m x n integer grid image where image\[i]\[j] represents the pixel value of the image.You are also given three integers s
15.[Leetcode] 695. Max Area of Island
You are given an m x n binary matrix grid. An island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) You may
16.[Leetcode]617. Merge Two Binary Trees
You are given two binary trees root1 and root2.Imagine that when you put one of them to cover the other, some nodes of the two trees are overlapped wh
17.[Leetcode]116. Populating Next Right Pointers in Each Node
📄 Description 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
18.[Leetcode]994. Rotting Oranges
📄 Description You are given an `m x n` grid where each cell can have one of three values: - `0` representing an empty cell, - `1` representing a
19.[Leetcode]100. Same Tree
Given the roots of two binary trees p and q, write a function to check if they are the same or not.Two binary trees are considered the same if they ar
20.[Leetcode]101. Symmetric Tree
📄 Description Given the root of a binary tree, check whether it is a mirror of itself (i.e., symmetric around its center).
21.[Leetcode]112. Path Sum
Given the root of a binary tree and an integer targetSum, return true if the tree has a root-to-leaf path such that adding up all the values along the
22.[Leetcode] 111. Minimum Depth of Binary Tree
📄 Description Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down
23.[Leetcode] 704. Binary Search
📄 Description Given an array of integers nums which is sorted in ascending order, and an integer target, write a function to search target in nums. I
24.[Leetcode] 121. Best Time to Buy and Sell Stock
📄 Description You are given an array prices where prices[i] is the price of a given stock on the ith day. You want to maximize your profit by choosi
25.[Leetcode]14. Longest Common Prefix
Write a function to find the longest common prefix string amongst an array of strings.If there is no common prefix, return an empty string "".1 <=
26.[Leetcode]643. Maximum Average Subarray I
You are given an integer array nums consisting of n elements, and an integer k.Find a contiguous subarray whose length is equal to k that has the maxi
27.[Leetcode]209. Minimum Size Subarray Sum
📄 Description Given an array of positive integers nums and a positive integer target, return the minimal length of a contiguous subarray $[nums{l}, n
28.[Leetcode]2185. Counting Words With a Given Prefix
You are given an array of strings words and a string pref.Return the number of strings in words that contain pref as a prefix.A prefix of a string s i
29.[Leetcode]28. Implement strStr()
Implement strStr().Given two strings needle and haystack, return the index of the first occurrence of needle in haystack, or -1 if needle is not part
30.[Leetcode]860. Lemonade Change
📄 Description At a lemonade stand, each lemonade costs $5. Customers are standing in a queue to buy from you and order one at a time (in the order sp
31.[Leetcode]455. Assign Cookies
Assume you are an awesome parent and want to give your children some cookies. But, you should give each child at most one cookie.Each child i has a gr
32.[Leetcode]66. Plus One
You are given a large integer represented as an integer array digits, where each digits\[i] is the $i^{th}$ digit of the integer. The digits are order
33.[Leetcode]605. Can Place Flowers
You have a long flowerbed in which some of the plots are planted, and some are not. However, flowers cannot be planted inadjacent plots.Given an integ
34.[Leetcode]561. Array Partition I
Given an integer array nums of 2n integers, group these integers into n pairs (a1, b1), (a2, b2), ..., (an, bn) such that the sum of min(ai, bi) for a
35.[Leetcode]409. Longest Palindrome
Given a string s which consists of lowercase or uppercase letters, return the length of the longest palindrome that can be built with those letters.Le
36.[Leetcode]392. Is Subsequence
Given two strings s and t, return true if s is a subsequence of t, or false otherwise.A subsequence of a string is a new string that is formed from th
37.[Leetcode]406. Queue Reconstruction by Height
You are given an array of people, people, which are the attributes of some people in a queue (not necessarily in order). Each people\[i] = $h_i$, $k_i
38.[Leetcode]349. Intersection of Two Arrays
Given two integer arrays nums1 and nums2, return an array of their intersection. Each element in the result must be unique and you may return the resu
39.[Leetcode]125. Valid Palindrome
A phrase is a palindrome if, after converting all uppercase letters into lowercase letters and removing all non-alphanumeric characters, it reads the
40.[Leetcode]937. Reorder Data in Log Files
You are given an array of logs. Each log is a space-delimited string of words, where the first word is the identifier.There are two types of logs:Lett
41.[Leetcode]819. Most Common Word
Given a string paragraph and a string array of the banned words banned, return the most frequent word that is not banned. It is guaranteed there is at
42.[Leetcode]49. Group Anagrams
Given an array of strings strs, group the anagrams together. You can return the answer in any order.An Anagram is a word or phrase formed by rearrangi
43.[Leetcode]2124. Check if All A's Appears Before All B's
Given a string s consisting of only the characters 'a' and 'b', return true if every 'a' appears before every 'b' in the string. Otherwise, return fal
44.[Programmers] 카카오 코테 기출 - Lv2. 뉴스 클러스터링
45.[Leetcode]332. Reconstruct Itinerary
Referenceshttps://leetcode.com/problems/reconstruct-itinerary/
46.[Leetcode]787. Cheapest Flights Within K Stops
There are n cities connected by some number of flights. You are given an array flights where flights\[i] = $from_i$, $to_i$, $price_i$ indicates that
47.Python으로 준비하는 코딩테스트 - 나의 Cheat Seet!
인덱싱: 지정된 인덱스의 값을 return 받기 떄문에 해당 인덱스 값이 없으면 error 발생인덱스 슬라이싱: 해당하는 sequence를 return 받기 때문에 해당 sequence가 없으면 빈 배열을 return이게 어느 문제에서 썼던 거더라..
48.[CodeSignal] Arcade - Smooth Sailing(14) reverseInParentheses
Write a function that reverses characters in (possibly nested) parentheses in the input string. Input strings will always be well-formed with matching
49.[CodeSignal] Arcade - Exploring the Waters (16) Add Border
Given a rectangular matrix of characters, add a border of asterisks(\*) to it.Forthe output should beexecution time limit 4 seconds (py3)input array.s
50.[Leetcode]463. Island Perimeter
📄 Description You are given row x col grid representing a map where gridi = 1 represents land and gridi = 0 represents water. Grid cells are connect
51.[Leetcode] 290. Word Pattern
Given a pattern and a string s, find if s follows the same pattern.Here follow means a full match, such that there is a bijection between a letter in
52.[Leetcode] 763. Partition Labels
You are given a string s. We want to partition the string into as many parts as possible so that each letter appears in at most one part.Note that the
53.[Leetcode]1379. Find a Corresponding Node of a Binary Tree in a Clone of That Tree
Given two binary trees original and cloned and given a reference to a node target in the original tree.The cloned tree is a copy of the original tree.
54.[Leetcode]1791. Find Center of Star Graph
업로드중..There is an undirected star graph consisting of n nodes labeled from 1 to n. A star graph is a graph where there is one center node and exactly
55.[Leetcode]1791. Find Center of Star Graph
업로드중..There is an undirected star graph consisting of n nodes labeled from 1 to n. A star graph is a graph where there is one center node and exactly
56.[Leetcode]1791. Find Center of Star Graph
업로드중..There is an undirected star graph consisting of n nodes labeled from 1 to n. A star graph is a graph where there is one center node and exactly
57.[Leetcode]1791. Find Center of Star Graph
업로드중..There is an undirected star graph consisting of n nodes labeled from 1 to n. A star graph is a graph where there is one center node and exactly
58.[Leetcode]1791. Find Center of Star Graph
업로드중..There is an undirected star graph consisting of n nodes labeled from 1 to n. A star graph is a graph where there is one center node and exactly
59.[Leetcode] 1971. Find if Path Exists in Graph
There is a bi-directional graph with n vertices, where each vertex is labeled from 0 to n - 1 (inclusive). The edges in the graph are represented as a
60.[Leetcode]997. Find the Town Judge
In a town, there are n people labeled from 1 to n. There is a rumor that one of these people is secretly the town judge.If the town judge exists, then
61.[Leetcode]1020. Number of Enclaves
You are given an m x n binary matrix grid, where 0 represents a sea cell and 1 represents a land cell.A move consists of walking from one land cell to
62.[Leetcode]1254. Number of Closed Islands
Given a 2D grid consists of 0s (land) and 1s (water). An island is a maximal 4-directionally connected group of 0s and a closed island is an island t
63.[Leetcode]1905. Count Sub Islands
You are given two m x n binary matrices grid1 and grid2 containing only 0's (representing water) and 1's (representing land). An island is a group of
64.[Leetcode]187. Repeated DNA Sequences
The DNA sequence is composed of a series of nucleotides abbreviated as 'A', 'C', 'G', and 'T'.For example, "ACGAATTCCG" is a DNA sequence.When studyin
65.[CodeSignal] Arcade - Island of Knowledge (24) Box Blur
📄 Description Last night you partied a little too hard. Now there's a black and white photo of you that's about to go viral! You can't let this ruin
66.[CodeSignal] Arcade - Island of Knowledge (25) MineSweeper
업로드중..In the popular Minesweeper game you have a board with some mines and those cells that don't contain a mine have a number in it that indicates th
67.[Leetcode]198. House Robber
업로드중..You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopp
68.[프로그래머스] JadenCase 문자열 만들기
JadenCase란 모든 단어의 첫 문자가 대문자이고, 그 외의 알파벳은 소문자인 문자열입니다. 단, 첫 문자가 알파벳이 아닐 때에는 이어지는 알파벳은 소문자로 쓰면 됩니다. (첫 번째 입출력 예 참고)문자열 s가 주어졌을 때, s를 JadenCase로 바꾼 문자열을
69.[프로그래머스] 최솟값 만들기
길이가 같은 배열 A, B 두개가 있습니다. 각 배열은 자연수로 이루어져 있습니다.배열 A, B에서 각각 한 개의 숫자를 뽑아 두 수를 곱합니다. 이러한 과정을 배열의 길이만큼 반복하며, 두 수를 곱한 값을 누적하여 더합니다. 이때 최종적으로 누적된 값이 최소가 되도록
70.[프로그래머스] 올바른 괄호
업로드중..괄호가 바르게 짝지어졌다는 것은 '(' 문자로 열렸으면 반드시 짝지어서 ')' 문자로 닫혀야 한다는 뜻입니다. 예를 들어"()()" 또는 "(())()" 는 올바른 괄호입니다.")()(" 또는 "(()(" 는 올바르지 않은 괄호입니다.'(' 또는 ')' 로만
71.[프로그래머스] 이진 변환 반복하기
0과 1로 이루어진 어떤 문자열 x에 대한 이진 변환을 다음과 같이 정의합니다.x의 모든 0을 제거합니다.x의 길이를 c라고 하면, x를 "c를 2진법으로 표현한 문자열"로 바꿉니다.예를 들어, x = "0111010"이라면, x에 이진 변환을 가하면 x = "0111
72.[프로그래머스] 영어 끝말잇기
1부터 n까지 번호가 붙어있는 n명의 사람이 영어 끝말잇기를 하고 있습니다. 영어 끝말잇기는 다음과 같은 규칙으로 진행됩니다.1번부터 번호 순서대로 한 사람씩 차례대로 단어를 말합니다.마지막 사람이 단어를 말한 다음에는 다시 1번부터 시작합니다.앞사람이 말한 단어의 마
73.[프로그래머스] 영어 끝말잇기
1부터 n까지 번호가 붙어있는 n명의 사람이 영어 끝말잇기를 하고 있습니다. 영어 끝말잇기는 다음과 같은 규칙으로 진행됩니다.1번부터 번호 순서대로 한 사람씩 차례대로 단어를 말합니다.마지막 사람이 단어를 말한 다음에는 다시 1번부터 시작합니다.앞사람이 말한 단어의 마
74.[프로그래머스] 구명보트
무인도에 갇힌 사람들을 구명보트를 이용하여 구출하려고 합니다. 구명보트는 작아서 한 번에 최대 2명씩 밖에 탈 수 없고, 무게 제한도 있습니다.예를 들어, 사람들의 몸무게가 \[70kg, 50kg, 80kg, 50kg]이고 구명보트의 무게 제한이 100kg이라면 2번째
75.[프로그래머스] 괄호 회전하기
다음 규칙을 지키는 문자열을 올바른 괄호 문자열이라고 정의합니다.(), \[], {} 는 모두 올바른 괄호 문자열입니다.만약 A가 올바른 괄호 문자열이라면, (A), \[A], {A} 도 올바른 괄호 문자열입니다. 예를 들어, \[] 가 올바른 괄호 문자열이므로, (\
76.[프로그래머스] DFS/BFS
네트워크 게임 맵 최단거리
77.[프로그래머스] 숫자의 표현
Finn은 요즘 수학공부에 빠져 있습니다. 수학 공부를 하던 Finn은 자연수 n을 연속한 자연수들로 표현 하는 방법이 여러개라는 사실을 알게 되었습니다. 예를들어 15는 다음과 같이 4가지로 표현 할 수 있습니다.1 + 2 + 3 + 4 + 5 = 154 + 5 +
78.[프로그래머스] 단어 변환
두 개의 단어 begin, target과 단어의 집합 words가 있습니다. 아래와 같은 규칙을 이용하여 begin에서 target으로 변환하는 가장 짧은 변환 과정을 찾으려고 합니다.한 번에 한 개의 알파벳만 바꿀 수 있습니다.words에 있는 단어로만 변환할 수 있
79.[프로그래머스] 배달 - 다익스트라
N개의 마을로 이루어진 나라가 있습니다. 이 나라의 각 마을에는 1부터 N까지의 번호가 각각 하나씩 부여되어 있습니다. 각 마을은 양방향으로 통행할 수 있는 도로로 연결되어 있는데, 서로 다른 마을 간에 이동할 때는 이 도로를 지나야 합니다. 도로를 지날 때 걸리는 시
80.[프로그래머스] 방문 길이
게임 캐릭터를 4가지 명령어를 통해 움직이려 합니다. 명령어는 다음과 같습니다.U: 위쪽으로 한 칸 가기D: 아래쪽으로 한 칸 가기R: 오른쪽으로 한 칸 가기L: 왼쪽으로 한 칸 가기캐릭터는 좌표평면의 (0, 0) 위치에서 시작합니다. 좌표평면의 경계는 왼쪽 위(-5,
81.[프로그래머스] 햄버거 만들기
ingredient의 원소는 1, 2, 3 중 하나의 값이며, 순서대로 빵, 야채, 고기를 의미합니다.빵-야채-고기-빵 순서여야지만 햄버거를 만들 수 있다.만들 수 있는 햄버거의 개수는?햄버거가 만들어지면 stack을 슬라이싱하여 update하였다.하지만, 시간 복잡도
82.[프로그래머스] 옹알이(2)
문제: 예를 들어 yemaaya 같은 건 가능하다고 판단할 수 있지만, 두 번, 세 번 이상 반복되는 경우, 예를 들어 yemayeaya 같은 건 permutations으로 구할 수가 없다.따라서 두 번째 방법으로, 한 문자, 한 문자씩 확인해보았다.https: