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  1. #include <iostream>
  2.  
  3. unsigned long long fib_iter(unsigned long long n)
  4. {
  5.     unsigned long long n1 = 0;
  6. 	unsigned long long n2 = 1;
  7. 	unsigned long long temp = 0;
  8.  
  9. 	while ( --n )
  10. 	{
  11. 		temp = n2;
  12. 		n2 = n1 + n2;
  13. 		n1 = temp;
  14. 	}
  15.  
  16. 	return n2;
  17. }
  18.  
  19. unsigned long long fib_rek(unsigned long long n)
  20. {
  21. 	if ( n <= 1 )
  22. 		return n;
  23. 	else
  24. 		return fib_rek(n-1) + fib_rek(n-2);
  25. }
  26.  
  27. unsigned long long fib_tail_(unsigned long long n, unsigned long long f1, unsigned long long f2)
  28. {
  29. 	if ( n == 0 )
  30. 		return f2;
  31. 	else
  32. 		return fib_tail_(n-1, f2, f1+f2);
  33. }
  34.  
  35. unsigned long long fib_tail(unsigned long long n)
  36. {
  37. 	return fib_tail_(n, 1, 0);
  38. }
  39.  
  40. int main()
  41. {
  42. 	std::cout << "Iter:     " << fib_iter(48) << std::endl;
  43. 	std::cout << "Rek_Tail: " << fib_tail(48) << std::endl;
  44. 	std::cout << "Rek:      " << fib_rek(48) << std::endl;
  45.  
  46. 	return 0x0;
  47. }
Time limit exceeded #stdin #stdout 5s 2680KB
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Standard input is empty
stdout
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Iter:     4807526976
Rek_Tail: 4807526976
https://ideone.com/Kf5i6K
language:
C++ (gcc 8.3)
created:
13 years ago
visibility:
secret

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