# Category: Fundamentals

## Negate a number using addition operator

Problem: Given a number X, flip it to -X. Time complexity : O ( X ) Logic : The negation can be implemented by adding -1, X times. Solution :

## Implement a power function

Naive logic: Loop through the number of times the exponent, and during each iteration multiply the base If our exponent is 10,000 then our loop has to run 10,000 times. But we can optimize...

## Withdraw all money from bank account

Problem : You have some money in your bank account, the only function to withdraw money is Withdraw(value), if the value is greater than the money you have it returns 0, otherwise it withdraws...

## Print half pyramids using * as shown

Pattern 1 : * ** *** **** ***** Logic : i height Number of * (= i) 1 5 1 2 5 2 3 5 3 4 5 4 5 5 5 Solution :...

## Binary tree traversal

Problem description : Tree traversal (a.k.a tree search) is a form of graph traversal and refers to the process of visiting each node in a tree data structure, exactly once, in a systematic way....

## Create a binary search tree in javascript

Create a simple binary search tree data structure in javascript. Binary tree : It is a tree data structure in which each node has at most two children, which are referred to as the...

## Create a simple queue using javascript

Problem description : Create a simple queue data structure in javascript. Queue organizes data into the sequential order. It similar to the a queue of people waiting to get a bus ticket. It’s a...

## Check if an element exists in an array, based on that update an array

Problem description : Write a function which detects if the given element exists in an array or not. If it does not exist then adds it to an array If it does exist then...

## Determine character frequency in the given string

Problem description : Create a character frequency analysis table for the given string. Input : A string // “foo bar” Output : A JSON // {” “: 1, a: 1, b: 1, f: 1,...

## Convert the given array of elements to a string

Problem description : Write a function that converts a given array into a string. Input : An Array Output : A String Logic : Iterate through array concatenate the new element into the string...