## Multiply Two Numbers without using * (Multiplication Operator)

Write a C program to multiply two numbers without using * multiplication operator.

Given two numbers, both numbers are positive.  Write a program to multiply two numbers without using * multiplication operator.  Think for a moment how to solve this problem .

You can use multiple approaches to find the solution of a problem. In this tutorial, we will multiply two numbers using recursion as well as using iterative approach.

C Program to Multiply Two Numbers without using *

## C Program to Reverse a Linked List using Recursion

Write a c program to reverse a linked list using recursion. Given a singly linked list, we have to write a code to reverse a linked list using recursion. This question is very important in terms of interviews.

In my previous post, I have explained C program to reverse a singly linked list. In this post, We are going to write a code to reverse a linked list using recursion.  If you are not familiar with the concept of recursion then check my previous tutorial on recursion vs iteration.

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The time complexity to reverse a linked list using recursion is O(n).

## C Program to Print Fibonacci Series using Recursion

Write a C program to print Fibonacci Series using recursion. Given an input number, we have to write a code to print Fibonacci series up to that number using Recursion.

This question is very important in terms of technical interviews.

You can check my previous post for PHP script to print Fibonacci series. Before solving this problem, Let’s first understand what is Recursion?

## What is Recursion?

In recursion, A function calls itself until the base condition is reached. Recursive code is much cleaner and shorter as compared to iterative code.
For better understanding you can check my previous post on recursion and what’s the difference between recursion and iteration.

For better understanding of  recursion concept, you can solve Objective Question on Recursion.

## Print Fibonacci Series in PHP

Write a code to print fibonacci series in PHP. In this tutorial, We are going to learn how to  write a fibonacci series program in PHP using recursion as well using iterative approach.

Given a number N, we have to write a PHP script which prints Fibonacci series from 1 to N, where N is an input integer.

## How to Find Duplicates in Array

Given an unsorted array. How to find duplicates in array using PHP. These types of questions are generally asked in interviews. Sometimes interviewer allows to use in-built function sometimes not.