You will now use the time and difftime functions to find out which function (pow

Question

You will now use the time and difftime functions to find out which function (pow or sqrt) is more efficient in calculating the square root of a number. Follow the indications in the following code to complete the program.

COMPLETE THE CODE IN BOLD

Please help with this practice problem...

//Calculate the square root of a number using sqrt and pow

#include <iostream>

#include <cmath>

#include <ctime>

using namespace std;

int main ()

{

    time_t before;

    time_t after;

    double x;

    double result;

    int i;

    //number of times pow and sqrt will be called:

    const int ITERATIONS = 1;

    cout << "Enter a (double) value: ";

    cin >> x;

    //your code goes here: record the time before using pow

    for (i = 0; i < ITERATIONS; i++)

        result = pow(x,0.5);

    //your code goes here: record the time after using pow

    cout << "pow(" << x << ", 0.5) = " << result << endl;

    //complete the following lines so that

    //the appropriate value is displayed

    cout << "Operation was calculated in ";

    cout << **your code goes here** << " seconds." << endl;

    //your code goes here: record the time before using sqrt

    for (i = 0; i < ITERATIONS; i++)

        result = sqrt(x);

    //your code goes here: record the time after using sqrt

    cout << "sqrt(" << x << ") = " << result << endl;

    //complete the following lines so that

    //the appropriate value is displayed

    cout << "Operation was calculated in ";

    cout << **your code goes here** << " seconds." << endl;

    return 0;

}

Explanation / Answer

//Calculate the square root of a number using sqrt and pow
#include <iostream>
#include <cmath>
#include <ctime>

using namespace std;

int main ()
{
time_t before;
time_t after;

double x;
double result;

int i;

//number of times pow and sqrt will be called:
const int ITERATIONS = 1;

cout << "Enter a (double) value: ";
cin >> x;

//your code goes here: record the time before using pow
time(&before);

for (i = 0; i < ITERATIONS; i++)
result = pow(x,0.5);
//your code goes here: record the time after using pow
time(&after);

cout << "pow(" << x << ", 0.5) = " << result << endl;
//complete the following lines so that
//the appropriate value is displayed
cout << "Operation was calculated in ";
cout << difftime(after,before) << " seconds." << endl;

//your code goes here: record the time before using sqrt
time(&before);

for (i = 0; i < ITERATIONS; i++)
result = sqrt(x);
//your code goes here: record the time after using sqrt
time(&after);

cout << "sqrt(" << x << ") = " << result << endl;
//complete the following lines so that
//the appropriate value is displayed
cout << "Operation was calculated in ";
cout << difftime(after,before) << " seconds." << endl;

return 0;
}

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