scalbn() function in C++

The scalbn() function is defined in the cmath header file. This function is used to calculate the product of given number x and FLT_RADIX raised to the power n. Syntax:-

float scalbn(float x, int n); 

or

double scalbn(double x, int n); 

or

long double scalbn(long double x, int n); 

or

double scalbn(integral x, int n);  

Parameters:- This method takes two parameters:

• x: This represents the value of significand.
• n: This represents the value of the exponent.

Return Value: This function returns the product of given number x and FLT_RADIX raised to the power n. with the help of formula:

scalbn(x, n) = x * FLT_RADIXn

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

Below programs illustrate the above function:- Example 1:-

cpp

// C++ program to demonstrate
// example of scalbn() function.

#include <bits/stdc++.h>
using namespace std;

int main()
{
    int n = 7;
    int x = 5;
    int ans;

    ans = scalbn(x, n);
    cout << x << " * "
        << FLT_RADIX << "^"
        << n << " = "
        << ans << endl;

    return 0;
}

Output:

5 * 2^7 = 640

Example 2:-

cpp

// C++ program to demonstrate
// example of scalbn() function.

#include <bits/stdc++.h>
using namespace std;

int main()
{
    int n = 7;
    double x = 3.9;
    int ans;

    ans = scalbn(x, n);
    cout << x << " * "
        << FLT_RADIX << "^"
        << n << " = "
        << ans << endl;

    return 0;
}

Output:

3.9 * 2^7 = 499