Question

Lab 10A Measure the program execution time

One easy way to measure the program execution time is encapsulate the useful timing functionality of C++ chrono library, This is illustrated inhttps://www.learncpp.com/cpp-tutorial/8-16-timing-your-code/

The example usingChronoTimer.cpp (Github/m10) is an example program using this chrono Timer class object to measure the Sorting on on an integer array of 10000 random integers based on the Bubble Sort vs. the C++ built-in Sort (an https://www.quora.com/Which-sorting-algorithm-does-STL-standard-template-library-use-in-c++. )

Please measure the performance of sorting the same array used in the usingChronoTimer.cpp example between the Insertion Sort vs. the Selection Sort.

Starter

usingChronoTimer.cpp (Github/m10):

#include <chrono> // chrono
	#include <cstdlib> // srand, rand
	#include <ctime> // time
	#include <algorithm> // sort
	#include <iostream>
	class Timer {
	// Type aliases to make accessing nested type easier
	using clock_t = std::chrono::high_resolution_clock;
	using second_t = std::chrono::duration<double, std::ratio<1> >;
	std::chrono::time_point<clock_t> m_beg;
	public:
	Timer() : m_beg(clock_t::now()) {}
	void reset() { m_beg = clock_t::now(); }
	double elapsed() const {
	return std::chrono::duration_cast<second_t>(clock_t::now() - m_beg).count();
	}
	};
	void bubbleSort(int* a, int size) {
	for(int i=0; i<size; i++)
	for(int j=0; j<size-1; j++) {
	if(a[j] > a[j+1]) {
	int t = a[j]; a[j] = a[j+1]; a[j+1] = t;
	}
	}
	}
	void show(int *a) {
	for(int i=0; i<5; i++)
	std::cout << a[i] << " ";
	std::cout << std::endl;
	}
	int main() {
	const int Size = 10000;
	int array1[Size];
	int array2[Size];
	srand (time(NULL));
	int fill;
	for(int i=0; i<Size; i++) {
	array1[i] =array2[i] = rand() % 100003; // next prime 10X
	}
	show(array1);
	show(array2);
	Timer t1;
	bubbleSort(array1, Size);
	double run1 = t1.elapsed();
	show(array1);
	Timer t2;
	std::sort(array2, array2+Size);
	double run2 = t2.elapsed();
	show(array2);
	std::cout << "Bubble Sort Time: " << run1 << " seconds\n"
	<< "CPP Sort Time: " << run2 << " seconds\n"
	<< "Efficientcy: " << int( run1/run2 );
	return 0;
	}

Submit

• myInsertionVsSelectionSortTime.cpp
• test run result

Answer 1

cpp code:

#include <iostream>
#include <chrono> // chrono
#include <cstdlib> // srand, rand
#include <ctime> // time
#include <algorithm> // sort

using namespace std;

class Timer {
// Type aliases to make accessing nested type easier
using clock_t = std::chrono::high_resolution_clock;
using second_t = std::chrono::duration<double, std::ratio<1> >;
std::chrono::time_point<clock_t> m_beg;
  
public:
Timer() : m_beg(clock_t::now()) {}

void reset() { m_beg = clock_t::now(); }

double elapsed() const {
return std::chrono::duration_cast<second_t>(clock_t::now() - m_beg).count();
}
};

//insertion sort
void insertionSort(int* a, int size)
{
int key,i,j;
for (i = 1; i < size; i++)
{
key = a[i];
j = i-1;

while (j >= 0 && a[j] > key)
{
a[j+1] = a[j];
j = j-1;
}
a[j+1] = key;
}
}
//swap function
void swap(int *x, int *y)
{
int t = *x;
*x = *y;
*y = t;
}

//selection sort function
void selectionSort(int* a, int size)
{
int i, j, min_idx;

for (i = 0; i <size -1; i++)
{
min_idx = i;
for (j = i+1; j < size; j++)
if (a[j] < a[min_idx])
min_idx = j;

// Swap the found minimum element with the first element
swap(&a[min_idx], &a[i]);
}
}
void show(int *a) {
cout << endl;
for(int i=0; i<5; i++)
cout << a[i] << " ";
cout << endl;
}
int main()
{
const int Size = 10000;
int array1[Size];
int array2[Size];
srand (time(NULL));
int fill;

for(int i=0; i<Size; i++) {
array1[i] =array2[i] = rand() % 100003; // next prime 10X
}
//cout<<"size: "<<Size;
show(array1);
show(array2);

//insertion sort
Timer t1;

insertionSort(array1, Size);

double run1 = t1.elapsed();
show(array1);

Timer t2;
std::sort(array2, array2+Size);
double run2 = t2.elapsed();
show(array2);

std::cout << "\n\nInsertion Sort Time: " << run1 << " seconds\n"
<< "CPP Sort Time: " << run2 << " seconds\n"
<< "Efficientcy: " << int( run1/run2 )<<endl;

//selection sort
Timer tt1;

selectionSort(array1, Size);

run1 = tt1.elapsed();
show(array1);

Timer tt2;
std::sort(array2, array2+Size);
run2 = tt2.elapsed();
show(array2);

std::cout << "\n\nSelection Sort Time: " << run1 << " seconds\n"
<< "CPP Sort Time: " << run2 << " seconds\n"
<< "Efficientcy: " << int( run1/run2 )<<endl;

return 0;
}

output:

2 DAcppInsertionVsSelectionSortTime\bin\Debug InsertionVsSelectionSortTime.exe 8824 20143 30741 15986 32161 8824 20143 30741 15986 32161 2 3 10 13 14 2 3 10 13 14 Insertion Sort Time: 0.102006 seconds CPP Sort Time: 0.003 seconds Efficientcy: 34 2 3 10 13 14 2 3 10 13 14 Selection Sort Time: 0.18801 seconds CPP Sort Time 0.002001 seconds Efficientcy: 93 Process returned 0 <0xxecution tie 0.405 s Press any key to continue

//for any clarification, please do comments. if you found this solution useful, please do comments