A trie (pronounced as “try”) or prefix tree is a tree data structure used to efficiently store and retrieve keys in a dataset of strings. There are various applications of this data structure, such as autocomplete and spellchecker. Implement the Trie class: Input [“Trie”, “insert”, “search”, “search”, “startsWith”, “insert”, “search”] [[], [“apple”], [“apple”], [“app”], [“app”], [“app”], [“app”]] Output: [null,… Continue reading

# Category: C++

## C++ – Factory Design Pattern – Creation Design Pattern

The Factory design pattern is a creational design pattern that provides an interface for creating objects in a superclass, but allows subclasses to alter the type of objects that will be created. Here’s an example of how the Factory pattern might be implemented in C++: In this example, the Product class is an interface that… Continue reading

## LFU Cache Implementation – LeetCode

Design and implement a data structure for a Least Frequently Used (LFU) cache. Implement the LFUCache class: Example 1: Input [“LFUCache”, “put”, “put”, “get”, “put”, “get”, “get”, “put”, “get”, “get”, “get”] [[2], [1, 1], [2, 2], [1], [3, 3], [2], [3], [4, 4], [1], [3], [4]] Output [null, null, null, 1, null, -1, 3, null, -1, 3, 4] This… Continue reading

## Program to find power of a number

In computer programming, power is denoted by symbol ^ . To calculate the power y of a number x, we use x^y. For example Let’s say x = 2, y = 5 Output of x^y = 32. Below is the implementation of the same In the above program, the function pow() is used to calculate… Continue reading

## Calling C++ function from C

To Call a C++ function from C , you need to use extern “C” with the C++ function and call it from your C/C++ code. The extern “C” line tells the compiler that the external information sent to the linker should use C calling conventions and name mangling. Below is the implementation: This works only for non-member… Continue reading

## Program to find roots of Quadratic Equation C++

To find roots of Quadratic equation , we need to first calculate the determinant. Once the determinant is calculated then we will get the roots using the formula. Below is the program

## Program to find best possible denomination of input money

In this program, we will be finding possible denomination of money input from user. In this case we are assuming denomination as 1,5,10,25. For example if input money is 65 then denomination will be 25*2,10*1,5*1. Since we are trying to get best possible denomination such that we have least coins, so will store the denomination… Continue reading

## Infix to Postfix Expression Using Stack

In this post, we will see infix to postfix expression.

## Iterators and Ranges in C++

An iterator is a variable that points to an element of a data structure. The iterator begin points to the first element of a data structure, and the iterator end points to the position after the last element. Let’s look at the example below Where vector v contain these elements: [4, 3, 2, 5, 6,… Continue reading

## Maximum of all Subarrays of size K | LeetCode #239

You are given an array of integers nums, there is a sliding window of size k which is moving from the very left of the array to the very right. You can only see the k numbers in the window. Each time the sliding window moves right by one position. Return the max sliding window of size K Example 1: Input:… Continue reading