abs(), labs(), llabs() functions in C/C++

abs(), labs(), llabs() functions are defined in cstdlib header file. These functions return the absolute value of integer that is input to them as their argument.

1. abs() function: Input to this function is value of type int in C and value of type int, long int or long long int in C++. In C output is of int type and in C++ the output has same data type as input. Below is the sample C++ program to show working of abs() function. 

CPP

// CPP program to illustrate
// abs() function
#include <cstdlib>
#include <iostream>

using namespace std;

int main()
{
    int val1, val2;

    /// finding absolute value using
    /// abs() function.
    val1 = abs(22);
    val2 = abs(-43);

    cout << "abs(22) = " << val1 << "\n";
    cout << "abs(-43) = " << val2 << "\n";
    return 0;
}

Output: 
abs(22) = 22
abs(-43) = 43

Time Complexity: O(1)

Space Complexity: O(1)

1. labs() function: This is the long int version of abs() function. Both the input and output are of long int type. Below is the sample C++ program to show working of labs() function. 

CPP

// CPP program to illustrate
// labs() function
#include <cstdlib>
#include <iostream>

using namespace std;

int main()
{
    int val1, val2;

    /// finding absolute value using
    /// labs() function.
    val1 = labs(1234355L);
    val2 = labs(-4325600L);

    cout << "labs(1234355L) = " << val1 << "\n";
    cout << "labs(-4325600L) = " << val2 << "\n";
    return 0;
}

Output: 
labs(1234355L) = 1234355
labs(-4325600L) = 4325600

Time Complexity: O(1)

Space Complexity: O(1)

1. llabs() function: This is the long long int version of abs() function. Both the input and output are of long long int type. Below is the sample C++ program to show working of llabs() function. 

CPP

// CPP program to illustrate
// llabs() function
#include <cstdlib>
#include <iostream>

using namespace std;

int main()
{
    int val1, val2;

    /// finding absolute value using
    /// labs() function.
    val1 = llabs(1234863551LL);
    val2 = llabs(-432592160LL);

    cout << "llabs(1234863551LL) = " << val1 << "\n";
    cout << "llabs(-432592160LL) = " << val2 << "\n";
    return 0;
}

Output: 
llabs(1234863551LL) = 1234863551
llabs(-432592160LL) = 432592160

Time Complexity: O(1)

Space Complexity: O(1)