fork download
copy 
  1. #include <iostream>
  2.  
  3. double power(double x, unsigned pow, double _acc = 1)
  4. {
  5. 	if (pow == 0) return _acc;
  6. 	if (pow%2)
  7. 		return power(x, pow - 1, _acc * x);
  8. 	else
  9. 		return power(x * x, pow / 2, _acc);
  10. }
  11.  
  12. double power(double x, int y)
  13. {
  14. 	unsigned pow   = static_cast<unsigned>(y >= 0 ? y : -(y+1) + 1UL);
  15. 	double x_pow = power(x, pow);
  16. 	return (y >= 0 ? x_pow : 1. / x_pow);
  17. }
  18.  
  19. int main() 
  20. {
  21. 	std::cout << power(2, 5) << std::endl;
  22. 	std::cout << power(2.5, 3) << std::endl;
  23. 	std::cout << power(2, -5) << std::endl;
  24. 	std::cout << power(-1., 200000) << std::endl;
  25. }
Success #stdin #stdout 0s 15240KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
32
15.625
0.03125
1
https://ideone.com/rU520r
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!