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  1. #include <bits/stdc++.h>
  2. using namespace std;
  3. // FX 9.11: r,rho(r),m(r)
  4. // by Xellos
  5. // integrovane Eulerovou metodou
  6. // jednotky: SI zakladne
  7. typedef long double ld;
  8.  
  9. // konstanty
  10. ld R =8.314;						// univ. plynova konstanta
  11. ld G =6.67e-11;						// gravitacna konstanta
  12. ld M =2e-3;							// molova hmotnost H2
  13. ld pi =3.1415;
  14.  
  15. ld dif_rho(ld r, ld rho, ld m, ld T) {
  16. 	// d(rho)/dr
  17. 	return -G*M*rho*m/(R*T*pow(r,2));}
  18.  
  19. ld V(ld r) {
  20. 	// objem gule s polomerom r
  21. 	return 4*pi/3*pow(r,3);}
  22.  
  23. ld S(ld r) {
  24. 	// povrch gule s polomerom r
  25. 	return 4*pi*pow(r,2);}
  26.  
  27. int main() {
  28. 	cout << scientific << setprecision(4);
  29.  
  30. 	// vstupne parametre
  31. 	ld T;							// teplota mraku
  32. 	ld rho_c;						// hustota v strede
  33. 	ld m_t;							// hmotnost mraku
  34. 	cin >> T >> rho_c >> m_t;
  35.  
  36. 	// init ratanych premennych
  37. 	ld r =1e5;						// polomer
  38. 	ld rho =rho_c;					// rho(r)
  39. 	ld m =V(r)*rho;					// m(r)
  40.  
  41. 	int t =0, K =10000;				// vypisuj len kazdy K-ty riadok
  42.  
  43. 	while(m < m_t) {
  44. 		if((t++)%K == 0)
  45. 			cout << r << " " << rho << " " << m << "\n";
  46.  
  47. 		ld dr =r/1e6;				// krok
  48. 		rho +=dif_rho(r,rho,m,T)*dr;
  49. 		m +=S(r)*rho*dr;
  50. 		r +=dr;
  51.  
  52. 		if(rho < 0) {
  53. 			cout << "FAIL\n";
  54. 			return 0;}
  55. 		}
  56.  
  57. 	return 0;}
  58.  
Success #stdin #stdout 0s 3296KB
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https://ideone.com/aXPVSF
FX9 - 11
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
secret

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