Program to find absolute value of a given number

Given an integer N, the task is to find the absolute value of the given integer.
Examples:

Input: N = -6 
Output: 6
Input: N = 12 
Output: 12 

Method 1 – Naive Approach: Since the absolute value of any number is always positive. For any positive number, the absolute value is the number itself and for any negative number, the absolute value is (-1) multiplied by the negative number. 

C++

// C++ program for Method 1
#include <bits/stdc++.h>
using namespace std;

// Function to find the absolute value
void findAbsolute(int N)
{

    // If the number is less than
    // zero, then multiply by (-1)
    if (N < 0)
    {
        N = (-1) * N;
    }

    // Print the absolute value
    cout << " " << N;
}

// Driver Code
int main()
{

    // Given integer
    int N = -12;

    // Function call
    findAbsolute(N);
    return 0;
}

// This code is contributed by shivanisinghss2110

C

// C program for Method 1
#include <stdio.h>

// Function to find the absolute value
void findAbsolute(int N)
{

    // If the number is less than
    // zero, then multiply by (-1)
    if (N < 0) {
        N = (-1) * N;
    }

    // Print the absolute value
    printf("%d ", N);
}

// Driver Code
int main()
{

    // Given integer
    int N = -12;

    // Function call
    findAbsolute(N);
    return 0;
}

Java

// Java program for Method 1
class GFG{

// Function to find the absolute value
static void findAbsolute(int N)
{

    // If the number is less than
    // zero, then multiply by (-1)
    if (N < 0)
    {
        N = (-1) * N;
    }

    // Print the absolute value
    System.out.printf("%d ", N);
}

// Driver Code
public static void main(String[] args)
{

    // Given integer
    int N = -12;

    // Function call
    findAbsolute(N);
}
}

// This code is contributed by 29AjayKumar

Python3

# Python3 program for Method 1

# Function to find the absolute value
def findAbsolute(N):

    # If the number is less than
    # zero, then multiply by (-1)
    if (N < 0):
        N = (-1) * N;

    # Print the absolute value
    print(N);

# Driver code
if __name__ == '__main__':

    # Given integer
    N = -12;

    # Function call
    findAbsolute(N);

# This is code contributed by amal kumar choubey

C#

// C# program for Method 1
using System;
using System.Collections.Generic;

class GFG{

// Function to find the absolute value
static void findAbsolute(int N)
{

    // If the number is less than
    // zero, then multiply by (-1)
    if (N < 0)
    {
        N = (-1) * N;
    }

    // Print the absolute value
    Console.Write("{0} ", N);
}

// Driver Code
public static void Main(String[] args)
{

    // Given integer
    int N = -12;

    // Function call
    findAbsolute(N);
}
}

// This code is contributed by sapnasingh4991

Javascript

<script>
    // Javascript program for Method 1

    // Function to find the absolute value
    function findAbsolute(N)
    {

        // If the number is less than
        // zero, then multiply by (-1)
        if (N < 0)
        {
            N = (-1) * N;
        }

        // Print the absolute value
        document.write(" " + N);
    }


    // Given integer
    let N = -12;

    // Function call
    findAbsolute(N);

    // This code is contributed by suresh07.
</script>

Output:

12

Time Complexity: O(1)
Auxiliary Space: O(1)

Method 2 – Using Bitmasking: Since negative numbers are stored in 2s complement form, to get the absolute value, we have to toggle bits of the number and add 1 to the result. Below are the steps: 

1. Set the mask as right shift of integer by 31 (assuming integers are stored using 32 bits). 
   

mask = n >> 31

        2. For negative numbers, above step sets mask as 1 1 1 1 1 1 1 1 and 0 0 0 0 0 0 0 0 for positive numbers. Add the mask to the given number. 

mask + n

       3. XOR of mask +n and mask gives the absolute value. 

(mask + n)^mask  

C++

// C++ program for Method 2
#include <bits/stdc++.h>
using namespace std;
#define CHAR_BIT 8

// Function to find the absolute
// value
void findAbsolute(int N)
{

    // Find mask
    int mask = N >> (sizeof(int) * CHAR_BIT - 1);

    // Print the absolute value
    // by (mask + N)^mask
    cout << ((mask + N) ^ mask);
}

// Driver Code
int main()
{

    // Given integer
    int N = -12;

    // Function call
    findAbsolute(N);
    return 0;
}

// This code is contributed by Code_Mech

C

// C program for Method 2
#include <stdio.h>
#define CHAR_BIT 8

// Function to find the absolute
// value
void findAbsolute(int N)
{

    // Find mask
    int mask
        = N
          >> (sizeof(int) * CHAR_BIT - 1);

    // Print the absolute value
    // by (mask + N)^mask
    printf("%d ", (mask + N) ^ mask);
}

// Driver Code
int main()
{

    // Given integer
    int N = -12;

    // Function call
    findAbsolute(N);
    return 0;
}

Java

// Java program for Method 2
class GFG{

static final int CHAR_BIT = 8;

// Function to find the absolute value
static void findAbsolute(int N)
{

    // Find mask
    int mask = N >> (Integer.SIZE / 8 *
                         CHAR_BIT - 1);

    // Print the absolute value
    // by (mask + N)^mask
    System.out.printf("%d ", (mask + N) ^ mask);
}

// Driver Code
public static void main(String[] args)
{

    // Given integer
    int N = -12;

    // Function call
    findAbsolute(N);
}
}

// This code is contributed by 29AjayKumar

Python3

# Python3 program for Method 2
import sys

CHAR_BIT = 8;

# Function to find the absolute value
def findAbsolute(N):

    # Find mask
    mask = N >> (sys.getsizeof(int()) // 8 *
                              CHAR_BIT - 1);

    # Print the absolute value
    # by (mask + N)^mask
    print((mask + N) ^ mask);

# Driver Code
if __name__ == '__main__':

    # Given integer
    N = -12;

    # Function call
    findAbsolute(N);

# This code is contributed by 29AjayKumar

C#

// C# program for Method 2
using System;

class GFG{

static readonly int CHAR_BIT = 8;

// Function to find the absolute value
static void findAbsolute(int N)
{

    // Find mask
    int mask = N >> (sizeof(int) / 8 *
                        CHAR_BIT - 1);

    // Print the absolute value
    // by (mask + N)^mask
    Console.Write((mask + N) ^ mask);
}

// Driver Code
public static void Main(String[] args)
{

    // Given integer
    int N = -12;

    // Function call
    findAbsolute(N);
}
}

// This code is contributed by 29AjayKumar

Javascript

<script>
    // Javascript program for Method 2

    let CHAR_BIT = 8;

    // Function to find the absolute value
    function findAbsolute(N)
    {

        // Find mask
        let mask = N >> (4 / 8 * CHAR_BIT - 1);

        // Print the absolute value
        // by (mask + N)^mask
        document.write((mask + N) ^ mask);
    }

    // Given integer
    let N = -12;

    // Function call
    findAbsolute(N);

// This code is contributed by mukesh07.
</script>

Output:

12

Time Complexity: O(1)
Auxiliary Space: O(1)

Method 3 – Using inbuilt abs() function: The inbuilt function abs() in stdlib.h library finds the absolute value of any number.
Below is the implementation of the above approach: 

C++

// C++ program for Method 3
# include<bits/stdc++.h>
using namespace std;

// Function to find the absolute
// value
void findAbsolute(int N)
{

    // Find absolute
    int X = abs(N);

    // Print the absolute value
    cout << X;
}

// Driver Code
int main()
{

    // Given integer
    int N = -12;

    // Function call
    findAbsolute(N);
    return 0;
}

// This code is contributed by Nidhi_biet

C

// C program for Method 3

#include <stdio.h>
#include <stdlib.h>

// Function to find the absolute
// value
void findAbsolute(int N)
{

    // Find absolute
    int X = abs(N);

    // Print the absolute value
    printf("%d ", X);
}

// Driver Code
int main()
{

    // Given integer
    int N = -12;

    // Function call
    findAbsolute(N);
    return 0;
}

Java

// Java program for Method 3
class GFG{

// Function to find the absolute
// value
static void findAbsolute(int N)
{

    // Find absolute
    int X = Math.abs(N);

    // Print the absolute value
    System.out.printf("%d", X);
}

// Driver Code
public static void main(String[] args)
{

    // Given integer
    int N = -12;

    // Function call
    findAbsolute(N);
}
}

// This code is contributed by sapnasingh4991

Python3

# Python3 program for Method 3
import math

# Function to find the absolute
# value
def findAbsolute(N):

    # Find absolute
    X = abs(N);

    # Print the absolute value
    print(X);

# Driver Code

# Given integer
N = -12;

# Function call
findAbsolute(N);

# This code is contributed by Nidhi_biet

C#

// C# program for Method 3
using System;

class GFG{

// Function to find the absolute
// value
static void findAbsolute(int N)
{

    // Find absolute
    int X = Math.Abs(N);

    // Print the absolute value
    Console.Write("{0}", X);
}

// Driver Code
public static void Main(String[] args)
{

    // Given integer
    int N = -12;

    // Function call
    findAbsolute(N);
}
}

// This code is contributed by 29AjayKumar

Javascript

<script>
    // Javascript program for Method 3

    // Function to find the absolute
    // value
    function findAbsolute(N)
    {

        // Find absolute
        let X = Math.abs(N);

        // Print the absolute value
        document.write(X);
    }

    // Given integer
    let N = -12;

    // Function call
    findAbsolute(N);

</script>

Output:

12

Time Complexity: O(1)
Auxiliary Space: O(1)