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  1. #include<iostream>
  2. #include<cstdio>
  3. #include<cmath>
  4. using namespace std;
  5.  
  6. double eps;
  7. double a,b,c,d;
  8. double f(double x)
  9. {
  10. 	return a*x*x*x+b*x*x+c*x+d;
  11. }
  12.  
  13. int main()
  14. {
  15. 	cin>>a>>b>>c>>d;
  16. 	eps=1e-8;
  17. 	for(int i=-100;i<100;i++)
  18. 	{
  19. 		if(fabs(f(i))<eps)printf("%.2lf ",i);
  20. 		else if(fabs(f(i+1))<eps||f(i)*f(i+1)>0)continue;
  21. 		else
  22. 		{
  23. 			double l=i,r=i+1;
  24. 			while(r-l>1e-8)
  25. 			{
  26. 				double mid=(l+r)/2.0;
  27. 				if(f(mid)*f(l)>0)
  28. 				{
  29. 					l=mid;
  30. 				}
  31. 				else
  32. 				{
  33. 					r=mid;
  34. 				}
  35. 			}
  36. 			printf("%.2lf ",l);
  37. 		}
  38. 	}
  39. 	if(fabs(f(100))<eps)printf("%.2lf",100.0);
  40.  
  41. 	return 0;
  42. }
Success #stdin #stdout 0s 5324KB
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-6.17
https://ideone.com/vN7DDN
language:
C++ (gcc 8.3)
created:
2 days ago
visibility:
public

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