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++



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// 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

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C

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// 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;
}

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Java

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// 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

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Python3

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# 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

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C#

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// 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

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Output:

12

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++

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// 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

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C

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// 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;
}

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Java

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// 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

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Python3

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# 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

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C#

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// 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

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Output:

12

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++

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// 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

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C

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// 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;
}

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Java

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// 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

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Python3

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# 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

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C#

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// 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

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Output:

12

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