Given an array of unique integers preorder, return true if it is the correct preorder traversal sequence of a binary search t…
My memo and playground
My memo and playground
Given an array of unique integers preorder, return true if it is the correct preorder traversal sequence of a binary search t…
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 – …
The school cafeteria offers circular and square sandwiches at lunch break, referred to by numbers 0 and 1 respectively. All studen…
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 isl…
Given a string s containing only three types of characters: ‘(‘, ‘)’ and ‘*’, return true if s is&nb…
Given a string s of ‘(‘ , ‘)’ and lowercase English characters. Your task is to remove the minimum number of parentheses…
Given a string s, return the length of the longest substring that contains at most two distinct characters. Example 1: Input…
Given a string s of lower and upper case English letters. A good string is a string which doesn’t have two adjacent characters&nb…
A string is a valid parentheses string (denoted VPS) if and only if it consists of “(” and “)” characters only, and: We …
A string is a valid parentheses string (denoted VPS) if it meets one of the following: We can similarly define the nesting depth&n…