꿈꾸는공학도

C++ Object Oriented Programming(OOP), Overroad, Override 실습

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..

LRU Cache [Final 기출] (Hash Table,Linked List,Design,Doubly-Linked List)

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..

https://leetcode.com/problems/minimum-number-of-operations-to-move-all-balls-to-each-box/description/?envType=daily-question&envId=2025-01-06You have n boxes. You are given a binary string boxes of length n, where boxes[i] is '0' if the ith box is empty, and '1' if it contains one ball.In one operation, you can move one ball from a box to an adjacent box. Box i is adjacent to box j if abs(i - j)..

https://leetcode.com/problems/count-vowel-strings-in-ranges/description/?envType=daily-question&envId=2025-01-02You are given a 0-indexed array of strings words and a 2D array of integers queries.Each query queries[i] = [li, ri] asks us to find the number of strings present in the range li to ri (both inclusive) of words that start and end with a vowel.Return an array ans of size queries.length,..

https://leetcode.com/problems/minimum-cost-for-tickets/description/?envType=daily-question&envId=2024-12-31You have planned some train traveling one year in advance. The days of the year in which you will travel are given as an integer array days. Each day is an integer from 1 to 365.Train tickets are sold in three different ways:a 1-day pass is sold for costs[0] dollars,a 7-day pass is sold for..

https://leetcode.com/problems/count-ways-to-build-good-strings/description/?envType=daily-question&envId=2024-12-30Given the integers zero, one, low, and high, we can construct a string by starting with an empty string, and then at each step perform either of the following:Append the character '0' zero times.Append the character '1' one times.This can be performed any number of times.A good stri..

https://leetcode.com/problems/maximum-frequency-stack/description/Design a stack-like data structure to push elements to the stack and pop the most frequent element from the stack.Implement the FreqStack class:FreqStack() constructs an empty frequency stack.void push(int val) pushes an integer val onto the top of the stack.int pop() removes and returns the most frequent element in the stack.If t..

https://leetcode.com/problems/best-sightseeing-pair/description/?envType=daily-question&envId=2024-12-27You are given an integer array values where values[i] represents the value of the ith sightseeing spot. Two sightseeing spots i and j have a distance j - i between them.The score of a pair (i  values[i] + values[j] + i - j: the sum of the values of the sightseeing spots, minus the distance bet..

https://leetcode.com/problems/target-sum/description/?envType=daily-question&envId=2024-12-26You are given an integer array nums and an integer target.You want to build an expression out of nums by adding one of the symbols '+' and '-' before each integer in nums and then concatenate all the integers.For example, if nums = [2, 1], you can add a '+' before 2 and a '-' before 1 and concatenate the..