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  1. #include <cstdio>
  2. #include <ctime>
  3.  
  4. template<class T> struct Vector
  5. {
  6. 	T *b, *e;
  7. 	Vector(size_t n) : b(new T[n]), e(b + n) { }
  8. 	T &operator[](size_t i) { return b[i]; }
  9. 	T &at(size_t i) { if (i >= e - b) { throw "invalid"; } return b[i]; }
  10. };
  11.  
  12. #define at operator[]  // Comment this out to enable bounds-checking
  13.  
  14. int main(int argc, char **argv)
  15. {
  16. 	Vector<size_t> v(1 << 16);
  17. 	for (size_t *p = v.b; p != v.e; ++p) { *p = 1; }
  18. 	clock_t begin = clock();
  19. 	for (int j = 0; j < 1 << 12; ++j)
  20. 	{
  21. 		for (size_t i = 8, n = v.e - v.b; i < n; ++i)
  22. 		{
  23. 			v.at(i) += v.at(i - 8);
  24. 			v.at(i) ^= v.at(i - 7);
  25. 			v.at(i) -= v.at(i - 6);
  26. 			v.at(i) ^= v.at(i - 5);
  27. 			v.at(i) += v.at(i - 4);
  28. 			v.at(i) ^= v.at(i - 3);
  29. 			v.at(i) -= v.at(i - 2);
  30. 			v.at(i) ^= v.at(i - 1);
  31. 		}
  32. 	}
  33. 	clock_t end = clock();
  34. 	fprintf(stderr, "%u\n", clock() - begin);
  35. }
  36.  
Success #stdin #stdout #stderr 0.88s 3552KB
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Standard input is empty
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Standard output is empty
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880000
https://ideone.com/oJcxzN
language:
C++ (gcc 8.3)
created:
10 years ago
visibility:
secret

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