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  1. #include <iostream>
  2. #include <string>
  3. #include <cmath>
  4. using namespace std;
  5.  
  6. float my_sqrt(float n) {
  7. 	float best = 1;
  8. 	const float accuracy = 0.01;
  9. 	const float starting_step = accuracy * accuracy * accuracy;
  10. 	float step = starting_step;
  11. 	float step_diff = starting_step;
  12. 	int steps_no = 0;
  13. 	while (fabs(best*best - n) > accuracy) {
  14. 		if (steps_no == 10000) break;
  15. 		// cout << best << endl;
  16. 		steps_no++;
  17. 		if (best*best > n) {
  18. 			best -= step;
  19. 			step /= 2;
  20. 			step_diff = starting_step;
  21. 			// best -= step;
  22. 			// step = starting_step;
  23. 			// step_diff = starting_step;
  24. 		} else {
  25. 			step_diff *= 2;
  26. 			step += step_diff;
  27. 			best += step;
  28. 		}
  29. 	}
  30. 	cout << "in " << steps_no << " steps" << endl;
  31. 	return best;
  32. }
  33.  
  34. int main() {
  35. 	float result = my_sqrt(32100);
  36. 	cout << result << " ^ 2 = " << result * result << endl;
  37. 	return 0;
  38. }
Success #stdin #stdout 0s 15232KB
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Standard input is empty
stdout
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in 68 steps
179.165 ^ 2 = 32100
https://ideone.com/XS95B8
language:
C++14 (gcc 8.3)
created:
6 years ago
visibility:
public

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