꿈꾸는공학도

https://leetcode.com/problems/number-of-music-playlists/description/ Your music player contains n different songs. You want to listen to goal songs (not necessarily different) during your trip. To avoid boredom, you will create a playlist so that:Every song is played at least once.A song can only be played again only if k other songs have been played.Given n, goal, and k, return the number of po..

https://leetcode.com/problems/uncrossed-lines/description/You are given two integer arrays nums1 and nums2. We write the integers of nums1 and nums2 (in the order they are given) on two separate horizontal lines.We may draw connecting lines: a straight line connecting two numbers nums1[i] and nums2[j] such that:nums1[i] == nums2[j], andthe line we draw does not intersect any other connecting (no..

https://leetcode.com/problems/linked-list-components/description/You are given the head of a linked list containing unique integer values and an integer array nums that is a subset of the linked list values.Return the number of connected components in nums where two values are connected if they appear consecutively in the linked list. Example 1:Input: head = [0,1,2,3], nums = [0,1,3]Output: 2Exp..

https://leetcode.com/problems/find-the-prefix-common-array-of-two-arrays/description/?envType=daily-question&envId=2025-01-14You are given two 0-indexed integer permutations A and B of length n.A prefix common array of A and B is an array C such that C[i] is equal to the count of numbers that are present at or before the index i in both A and B.Return the prefix common array of A and B.A sequenc..

https://leetcode.com/problems/minimum-length-of-string-after-operations/description/?envType=daily-question&envId=2025-01-13You are given a string s.You can perform the following process on s any number of times:Choose an index i in the string such that there is at least one character to the left of index i that is equal to s[i], and at least one character to the right that is also equal to s[i]..

https://leetcode.com/problems/word-subsets/description/?envType=daily-question&envId=2025-01-10You are given two string arrays words1 and words2.A string b is a subset of string a if every letter in b occurs in a including multiplicity.For example, "wrr" is a subset of "warrior" but is not a subset of "world".A string a from words1 is universal if for every string b in words2, b is a subset of a..

C++과 관련된 시험에서 꼭 빠지지 않고 등장하는 것이 이 OOP 문제이다. OOP는 Class를 하나 만들어놓고, 그에 파생되는 객체를 가지고 노는 Programming이다. 이번에 해 볼 실습은, 2D Vector Class를 만들고, 해당 Class에 각 종 Operator를 Overroad 해본 뒤, OOP를 써서 Class 구현이 잘 되었는지 테스트 해보고, 2D Vector를 상속받은 Derived Class 3D Vector를 만들어 Class의 Inherit, Method의 Override를 잘 구현했는지 Test 해보겠다. 문제 풀이를 위한 Skeleton code는 아래와 같다.#include #include using namespace std;// Base class for 2D ve..

PostgreSQL과 관련된 공식문서는 아래 링크에서 확인하면 된다.https://www.postgresql.org/docs/17/index.html PostgreSQL 17.2 DocumentationPostgreSQL 17.2 Documentation The PostgreSQL Global Development Group Copyright © 1996–2024 The PostgreSQL Global Development Group Legal Notice Table of …www.postgresql.org PostgreSQL의 Parser 부분에 대한 코드는 아래 git에서 보면 된다.https://github.com/launchql/pgsql-parser GitHub - launchql/pgsql-p..

https://leetcode.com/problems/lru-cache/description/DBMS Buffer에 Data를 Replace 하는 대표적인 Algorithm 중 하나인 LRU 방법에 대해 Implementation을 해보는 실습을 해본다. 문제 Description은 아래와 같다.Design a data structure that follows the constraints of a Least Recently Used (LRU) cache.Implement the LRUCache class:LRUCache(int capacity) Initialize the LRU cache with positive size capacity.int get(int key) Return the value of ..

https://leetcode.com/problems/unique-binary-search-trees/description/Given an integer n, return the number of structurally unique BST's (binary search trees) which has exactly n nodes of unique values from 1 to n. Example 1:Input: n = 3Output: 5Example 2:Input: n = 1Output: 1 Constraints:1 그래도 가볍게나마 BST문제도 풀어봐야지..! Linked List , Tree 이런 걸 자꾸만 건들자 근데 이건,, Tree 문제라기보단 수학 문제 같다.. 흐음..  1. Python 일단..