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  1.     #include <iostream>
  2.  
  3.     #include <vector>
  4.     #include <random>
  5.     #include <chrono>
  6.     #include <algorithm>
  7.  
  8.     struct A {
  9.         A(int i = 0) : i(i) {}
  10.         int i;
  11.         static int nSwaps;
  12.  
  13.         friend void swap(A& l, A& r)
  14.         {
  15.             ++nSwaps;
  16.             std::swap(l.i, r.i);
  17.         }
  18.  
  19.         bool operator<(const A& r) const
  20.         {
  21.             return i < r.i;
  22.         }
  23.     };
  24.  
  25.     int A::nSwaps = 0;
  26.  
  27.     using std::chrono::high_resolution_clock;
  28.     using std::chrono::duration_cast;
  29.     using std::chrono::milliseconds;
  30.  
  31.  
  32.     int main()
  33.     {
  34.         std::vector<A> v(10000000);
  35.  
  36.         std::ranlux24_base gen(std::random_device{}());
  37.         std::generate(v.begin(), v.end(), [&gen]() {return gen();});
  38.  
  39.         auto s = high_resolution_clock::now();
  40.         std::sort(v.begin(), v.end());
  41.         std::cout << duration_cast<milliseconds>(high_resolution_clock::now() - s).count() 
  42.             << "ms with " << A::nSwaps << " swaps\n";
  43.  
  44.         A::nSwaps = 0;
  45.         s = high_resolution_clock::now();
  46.         std::shuffle(v.begin(), v.end(), gen);
  47.         std::cout << duration_cast<milliseconds>(high_resolution_clock::now() - s).count() 
  48.             << "ms with " << A::nSwaps << " swaps\n";
  49.     }
  50.  
Success #stdin #stdout 2.8s 3464KB
comments (?)
stdin 
Standard input is empty
stdout 
1206ms with 47566736 swaps
1386ms with 9999999 swaps
https://ideone.com/i6lXCx
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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