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  1. #include <sys/time.h>
  2. #include <bits/stdc++.h>
  3. using namespace std;
  4.  
  5. #define MAX_TIMER_NUM 256
  6. static double s_tmptime[MAX_TIMER_NUM] = {}; // [s]
  7. void stopwatch_start(int index)
  8. {
  9.     if (index >= MAX_TIMER_NUM) {
  10.         cout << "INVALID TIMER NUM, IGNORED: MAX_TIMER_NUM is " << MAX_TIMER_NUM<< endl;
  11.         return;
  12.     }
  13.     struct timeval tim;  
  14.     gettimeofday(&tim, NULL);  
  15.     s_tmptime[index] = tim.tv_sec+(tim.tv_usec / 1000000.0);  
  16. }
  17.  
  18. double stopwatch_end(int index)
  19. {
  20.     if (index >= MAX_TIMER_NUM) {
  21.         cout << "INVALID TIMER NUM, IGNORED: MAX_TIMER_NUM is " << MAX_TIMER_NUM<< endl;
  22.         return -1;
  23.     }
  24.     struct timeval tim;  
  25.     gettimeofday(&tim, NULL);  
  26.     return tim.tv_sec+(tim.tv_usec / 1000000.0) - s_tmptime[index];
  27. }
  28.  
  29. double get_clock_now(void)
  30. {
  31.     struct timeval tv;
  32.     gettimeofday(&tv, NULL);
  33.     return tv.tv_sec + (double)tv.tv_usec*1e-6;
  34. }
  35.  
  36.  
  37. #define rep(i,n) for(int i = 0; i < n; i++)
  38. #define ll long long
  39. vector<ll> a;
  40. vector<ll> b;
  41. int main(void) {
  42.     for (ll cycle = 1; cycle <= 10000000; cycle *= 10) {
  43.         cout << cycle << " ";
  44.  
  45.         {
  46.             stopwatch_start(0);
  47.             rep(i, cycle) {
  48.                 a.push_back(i);
  49.             }
  50.             double t = stopwatch_end(0);
  51.             cout << t << " ";
  52.             a.clear();
  53.         }
  54.  
  55.         {
  56. 	        b.reserve(cycle);
  57.             stopwatch_start(0);
  58.             rep(i, cycle) {
  59.                 b.push_back(i);
  60.             }
  61.             double t = stopwatch_end(0);
  62.             cout << t << " ";
  63. 	        b.clear();
  64.         }
  65.         cout << endl;
  66.     }
  67.  
  68.     return 0;
  69. }
  70.  
Success #stdin #stdout 0.55s 3568KB
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stdin
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Standard input is empty
stdout
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1 1.93657e-06 9.9407e-07 
10 9.91812e-06 1.03668e-06 
100 1.29824e-05 2.00153e-06 
1000 3.99676e-05 2.2085e-05 
10000 0.000570024 0.000163998 
100000 0.00524106 0.002793 
1000000 0.0243821 0.016225 
10000000 0.328684 0.160289
https://ideone.com/hqxrRC
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

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