How to compare two vectors — Problem statement You are assigned to put some amount of boxes onto one truck. You are given a 2D array boxTypes, where boxTypes[i] = [numberOfBoxes_i, numberOfUnitsPerBox_i]: numberOfBoxes_i is the number of boxes of type i. numberOfUnitsPerBox_i is the number of units in each box of the type i. You are also given…

How to find substrings without repeating characters — Problem statement Given a string s, find the length of the longest substring without repeating characters. Example 1 Input: s = "abcabcbb" Output: 3 Explanation: The answer is "abc", with a length of 3. Example 2 Input: s = "bbbbb" Output: 1 Explanation: The answer is "b", with the length of 1. Example 3 Input: s = "pwwkew" Output…

When advanced mathematics comes to solving a coding problem — Problem statement Given an integer n, return the least number of perfect square numbers that sum to n. A perfect square is an integer that is the square of an integer; in other words, it is the product of some integer with itself. …

How to rotate a matrix — Problem statement You are given an n x n 2D matrix representing an image. Rotate the image by 90 degrees (clockwise). You have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation. Example 1

How to compute the longest cycle in a permutation — Problem statement You are given an integer array nums of length n where nums is a permutation of the numbers in the range [0, n - 1]. You should build a set s[k] = {nums[k], nums[nums[k]], nums[nums[nums[k]]], ... } subjected to the following rule: The first element in s[k] starts with the…

With Complete Code in C++, Explanation, Complexity Analysis and Discussion — Problem statement Given two version numbers, version1 and version2, compare them. Version numbers consist of one or more revisions joined by a dot '.'. Each revision consists of digits and may contain leading zeros. Every revision contains at least one character. …

How std::vectors are ordered in C++ — Problem statement Given an array intervals where intervals[i] = [li, ri] represent the interval [li, ri), remove all intervals that are covered by another interval in the list. The interval [a, b) is covered by the interval [c, d) if and only if c <= a and b <= d. Return the…

With Complete Code in C++, Explanation, Complexity Analysis and Discussion — Problem statement Given two strings s and t, return true if t is an anagram of s, and false otherwise. An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once. Example 1 Input: s = "anagram", t =…

How a reversed iteration can improve performance — Problem statement Given an array of integers temperatures representing the daily temperatures, return an array answer such that answer[i] is the number of days you have to wait after the i-th day to get a warmer temperature. …