How to Find Top K Frequent Elements via Priority Queue or Sorting?
Suppose if you are given an array of N integers, how could you find out the top K elements based on its frequencies? For example, Input: nums = , …
Tag: C++ coding exercise
How to Transpose a 2D Matrix?
Given a 2D Matrix, return the transpose of it. The transpose of a matrix is the matrix flipped over it’s main diagonal, switching the row and column indices of …
C++ Coding Exercise – How to Merge Two Binary Trees?
Given two binary trees and imagine that when you put one of them to cover the other, some nodes of the two trees are overlapped while the others are …
C++ Coding Exercise – Find All Duplicates in an Array
Given an array of integers, 1 ≤ a ≤ n (n = size of array), some elements appear twice and others appear once. Find all the elements that appear …
C++ Coding Exercise – Find Letter Case Permutation with DFS
Given a string S, we can transform every letter individually to be lowercase or uppercase to create another string. Return a list of all possible strings we could create. …