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  1. #include <iostream>
  2. #include <cstdlib>
  3. #include <ctime>
  4. #include <algorithm>
  5. #include <cmath>
  6. #include <array>
  7. #include <iterator>
  8.  
  9.  
  10. int main(int, char*[]){
  11. 	using namespace std;
  12. 	srand(time(0));
  13.  
  14. 	// setup bins
  15. 	int total = 3;
  16. 	const int MAX_BINS = 10;
  17. 	array<int,MAX_BINS> bins;
  18.  
  19. 	// determine weighted distribution
  20. 	array<float,MAX_BINS> weights;
  21. 	generate(weights.begin(), weights.end(), [](){
  22. 		return rand()*1.f/RAND_MAX;
  23. 	});
  24. 	float weight_sum = accumulate(weights.begin(), weights.end(), 0.f);
  25.  
  26. 	// determine portions
  27. 	// use "extra" to accumulate fractional 
  28. 	float extra = 0;
  29. 	int used = 0;
  30. 	for ( int idx = 0; idx < MAX_BINS; ++idx ) {
  31. 		float actual = weights[idx]/weight_sum * total + extra;
  32. 		int count = (int)actual;
  33.  
  34. 		extra = fmodf(actual, 1.f);
  35. 		bins[idx] = count;
  36. 		used += count;
  37. 	}
  38.  
  39. 	// any accumulation error is added to the first bin
  40. 	int error = error;
  41. 	bins[0] += total - used;
  42.  
  43. 	// output results
  44. 	cout << "total:\t" << total
  45. 		<< "\nbins:\t";
  46.  
  47. 	copy(bins.begin(), bins.end(), ostream_iterator<int>(cout, "\t"));
  48. 	cout << "\nerror:" << error
  49. 		<< "\nextra:" << total - accumulate(bins.begin(),bins.end(),0) << '\n';
  50. }
Success #stdin #stdout 0s 3456KB
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stdin
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Standard input is empty
stdout
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total:	3
bins:	0	0	0	1	0	1	0	0	0	1	
error:0
extra:0
https://ideone.com/PBEL1x
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
public

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