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  1. #include <iostream>
  2. //this test will output the result and return number of iterations required
  3. int method1( int n ); //simple - bitwise
  4. int method2( int n ); //Kernigan's method
  5.  
  6. int main() {
  7. 	int n = 3526; //0110111000110 - 7 bits set
  8. 	int it1 = method1(n), it2 = method2(n); //iterations required
  9.  
  10. 	std::cout << "Iterations required method1: " << it1 << std::endl;
  11. 	std::cout << "Iterations required method2: " << it2 << std::endl;
  12.  
  13. 	return 0;
  14. }
  15.  
  16. int method1( int n )
  17. {
  18. 	int count = 0 , i;
  19. 	for( i = 0; n; ++i )
  20. 	{
  21. 		count += n & 1;
  22. 		n >>= 1;
  23. 	}
  24.  
  25. 	std::cout << "Bits set: " << count << std::endl;
  26. 	return( i);
  27.  
  28. }
  29.  
  30. int method2( int n )
  31. {
  32. 	int i;
  33. 	for( i = 0; n; ++i )
  34. 	{
  35. 		n &= n - 1;
  36. 	}
  37. 	std::cout << "Bits set: " << i << std::endl;
  38. 	return( i );
  39. }
  40.  
Success #stdin #stdout 0s 3340KB
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stdin
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Standard input is empty
stdout
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Bits set: 7
Bits set: 7
Iterations required method1: 12
Iterations required method2: 7
https://ideone.com/Zyzsis
language:
C++14 (gcc 8.3)
created:
10 years ago
visibility:
public

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