Multiply a number with 10 without using multiplication operator

1.6

Given a number, the task is to multiply it with 10 without using multiplication operator?

Examples:

Input : n = 50
Output: 500
// multiplication of 50 with 10 is = 500

Input : n = 16
Output: 160
// multiplication of 16 with 10 is = 160

A simple solution for this problem is to run a loop and add n with itself 10 times. Here we need to perform 10 operations.
A better solution is to use bit manipulation. We have to multiply n with 10 i.e; n*10, we can write this as n*(2+8) = n*2 + n*8 and since we are not allowed to use multiplication operator we can do this using left shift bitwise operator. So n*10 = n<<1 + n<<3.

C++

// C++ program to multiply a number with 10 using
// bitwise operators
#include<bits/stdc++.h>
using namespace std;

// Function to find multiplication of n with
// 10 without usng multiplication operator
int multiplyTen(int n)
{
    return (n<<1) + (n<<3);
}

// Driver program to run the case
int main()
{
    int n = 50;
    cout << multiplyTen(n);
    return 0;
}

Java

// JAVA Code to Multiply a number with 10
// without using multiplication operator
import java.util.*;

class GFG {
    
    // Function to find multiplication of n 
    // with 10 without usng multiplication
    // operator
    public static int multiplyTen(int n)
    {
        return (n << 1) + (n << 3);
    }
    
    /* Driver program to test above function */
    public static void main(String[] args) 
    {
        int n = 50;
        System.out.println(multiplyTen(n));
       
    }
}
  
// This code is contributed by Arnav Kr. Mandal.


Output:

500

This article is contributed by Shashank Mishra ( Gullu ). If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

GATE CS Corner    Company Wise Coding Practice

Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.

Recommended Posts:



1.6 Average Difficulty : 1.6/5.0
Based on 12 vote(s)










Writing code in comment? Please use ide.geeksforgeeks.org, generate link and share the link here.