#include <iostream>
#include <cstdlib>
#include <time.h>
#include <sys/resource.h>

using namespace std;

double get_cpu_time()
{ struct rusage ruse;
  getrusage(RUSAGE_SELF, &ruse);
  return ruse.ru_utime.tv_sec+ruse.ru_utime.tv_usec/1000000.0 + 
         ruse.ru_stime.tv_sec+ruse.ru_stime.tv_usec/1000000.0; }

void selection_sort(string A[], int N)
{ int sum = 0;
  for (int i = 0; i < N; i += 1)
    for (int j = 0; j < N; j += 1)
      sum += 1; }

void bubble_sort(string A[], int N)
{ int sum = 0;
  for (int i = 0; i < N; i += 1)
    for (int j = 0; j < i; j += 1)
      sum += 1; }

string random_string()
{ string s = "";
  for (int i = 0; i < 10; i += 1)
    s += "abcdefghijklmnopqrstuvwxyz"[random() % 26];
  return s; }

int main(int argc, char * argv[])
{
  srandomdev();
  cout << "The command line contained:\n";
  for (int i = 0; i < argc; i += 1)
    cout << i << ": " << argv[i] << "\n"; 
  int N = atoi(argv[1]);
 
 string * A1 = new string[N];
  for (int i = 0; i < N; i += 1)
    A1[i] = random_string();
  string * A2 = new string[N];
  for (int i = 0; i < N; i += 1)
    A2[i] = A1[i];

  double t1 = get_cpu_time();
  selection_sort(A1, N);
  double t2 = get_cpu_time();
  bubble_sort(A2, N);
  double t3 = get_cpu_time();

  cout << "selection sort took " << t2-t1 << " seconds\n";
  cout << "bubble sort took " << t3-t2 << " seconds\n";
}