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  1. #include <cstdio>
  2. #include <limits>
  3.  
  4. #include <cstdint>
  5. #include <vector>
  6. #include <string>
  7. #include <cstdio>
  8. #include <iostream>
  9.  
  10. unsigned long factorial1(unsigned long(*self)(unsigned long), unsigned long n) {
  11. 	return n ? n * self(n - 1) : 1;
  12. }
  13.  
  14. template<class X, X(*Fn)(X(*)(X), X)>
  15. struct Fix {
  16. 	static X Function(X x) {
  17. 		return Fn(Fix<X, Fn>::Function, x);
  18. 	}
  19. };
  20.  
  21. unsigned long factorial(unsigned long n) {
  22. 	return Fix<unsigned long, factorial1>::Function(n);
  23. };
  24.  
  25. int main() {
  26. 	std::cout << factorial(1) << '\n';
  27. 	std::cout << factorial(2) << '\n';
  28. 	std::cout << factorial(3) << '\n';
  29. 	std::cout << factorial(4) << '\n';
  30. 	std::cout << factorial(5) << '\n';
  31. }
Success #stdin #stdout 0s 15240KB
comments ()
stdin 
Standard input is empty
stdout 
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https://ideone.com/pskx0X
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
public

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