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  1. #include <iostream>
  2. #include <vector>
  3. #include <chrono>
  4. #include <cstring>
  5.  
  6. const int SIZE = 1024*1024;
  7.  
  8. void WithArray()
  9. {
  10. 	using namespace std;
  11. 	char* a = new char[SIZE];
  12. 	auto b = &a[0];
  13. 	auto e = &a[SIZE];
  14.  
  15. 	memset(a, 0, sizeof a);
  16. 	int total=0;
  17.  
  18. 	auto begin = chrono::system_clock::now();
  19. 	for(int c=0; c<100; c++) {
  20. 		for(auto p=b; p<e;) {
  21. 			total += *p++;
  22. 		}
  23. 	}
  24. 	auto end  = chrono::system_clock::now();
  25. 	cout << total << ":" << chrono::duration_cast<chrono::milliseconds>(end-begin).count() << endl;
  26. 	delete[] a;
  27.  
  28. }
  29.  
  30. void WithVector()
  31. {
  32. 	using namespace std;
  33. 	vector<char> a(SIZE);
  34. 	auto b = a.begin();
  35. 	auto e = a.end();
  36. 	int total=0;
  37.  
  38. 	auto begin = chrono::system_clock::now();
  39. 	for(int c=0; c<100; c++) {
  40. 		for(auto it=b; it<e;) {
  41. 			total += *it++;
  42. 		}
  43. 	}
  44. 	auto end  = chrono::system_clock::now();
  45. 	cout << total << ":" << chrono::duration_cast<chrono::milliseconds>(end-begin).count() << endl;
  46. }
  47.  
  48. int main()
  49. {
  50. 	WithArray();
  51. 	WithVector();
  52. 	WithArray();
  53. 	WithVector();
  54. }
  55.  
Success #stdin #stdout 0.57s 3300KB
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https://ideone.com/S7i2Qa
language:
C++14 (gcc 8.3)
created:
11 years ago
visibility:
public

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