LeetCode 2285 solution

2285. Maximum Total Importance of Roads #Greedy #Graph #Sorting #Heap(Priority Queue) problem You are given an integer n denoting the number of cities in a country. The cities are numbered from 0 to n - 1. You are also given a 2D integer array roads where roads[i] = [ai,

[Blind75] Best time to buy and sell stock

121. Best Time to Buy and Sell Stock #Array #Dynamic Programming #blind75/2 problem 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 choosing a single day to buy one stock and

[Blind75] Two Sum

1. Two Sum #Array #Hash_table #blind75/1 problem 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 input would have exactly one solution, and you may not use the same

LeetCode 2073 solution

2073. Time Needed to Buy Tickets #Easy #Queue problem There are n people in a line queuing to buy tickets, where the 0th person is at the front of the line and the (n - 1)th person is at the back of the line. You are given a 0-indexed

LeetCode 1700 solution

1700. Number of Students Unable to Eat Lunch #Easy #Queue problem The school cafeteria offers circular and square sandwiches at lunch break, referred to by numbers 0 and 1 respectively. All students stand in a queue. Each student either prefers square or circular sandwiches. The number of sandwiches in the

LeetCode 678 solution

678. Valid Parenthesis String #Medium #stack #dp problem Given a string s containing only three types of characters: '(', ')' and '*', return true if s is valid. The following rules define a valid string: * Any left parenthesis '(' must have a corresponding right parenthesis '

LeetCode 1249 solution

1249. Minimum Remove to Make Valid Parentheses #Medium #stack problem Given a string s of '(' , ')' and lowercase English characters. Your task is to remove the minimum number of parentheses ('(' or ')', in any positions) so that the resulting parentheses string is valid and

LeetCode 1544 solution

1544. Make The String Great #Easy #Stack problem Given a string s of lower and upper case English letters. A good string is a string which doesn't have two adjacent characters s[i] and s[i + 1] where: * 0 <= i <= s.length - 2 * s[i]

LeetCode 1614 solution

1614. Maximum Nesting Depth of the Parentheses #Easy #Stack problem A string is a valid parentheses string (denoted VPS) if it meets one of the following: * It is an empty string "", or a single character not equal to "(" or ")", * It can be written as

LeetCode 205 solution

205. Isomorphic Strings #Hash_table #String problem 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

LeetCode 58 solution

58. Length of Last WordSolved #Easy #String problem Given a string s consisting of words and spaces, return the length of the last word in the string. A word is a maximal  substring consisting of non-space characters only. Example 1: * Input: s = "Hello World" * Output: 5 * Explanation: The

Python String method

가끔 알고리즘을 풀다 보면 string method를 필요로 할 경우들이 있다. 아주 쉬운 문제인 경우는 string method를 이용하면 순식간에 풀 수 있다. 하지만 기억이 가물가물할 경우에는 한참을 돌아가야 한다. 때문에 이에 대해서 document를 보면서 정리한다.