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  1. #include <iostream>
  2. #include <iomanip>
  3. #include <random>
  4. #include <cmath>
  5.  
  6. using namespace std;
  7.  
  8. // liczba podziałów / losowań (MOŻESZ zmienić tutaj)
  9. const long long n = 10000000;  
  10.  
  11. long double f(long double x) {
  12.     return 4.0L / (1.0L + x * x);
  13. }
  14.  
  15. int main() {
  16.  
  17.     // ================= MONTE CARLO =================
  18.     mt19937_64 gen(123456); // stałe ziarno – zawsze ten sam wynik
  19.     uniform_real_distribution<long double> dist(-1.0L, 1.0L);
  20.  
  21.     long long inside = 0;
  22.  
  23.     for(long long i = 0; i < n; i++) {
  24.         long double x = dist(gen);
  25.         long double y = dist(gen);
  26.  
  27.         if(x*x + y*y <= 1.0L)
  28.             inside++;
  29.     }
  30.  
  31.     long double pi_monte_carlo = 4.0L * inside / (long double)n;
  32.  
  33.     // ================= PROSTOKĄTY =================
  34.     long double dx = 1.0L / (long double)n;
  35.     long double sum_rect = 0.0L;
  36.  
  37.     for(long long i = 0; i < n; i++) {
  38.         long double x = i * dx;
  39.         sum_rect += f(x);
  40.     }
  41.  
  42.     long double pi_rect = sum_rect * dx;
  43.  
  44.     // ================= TRAPEZY =================
  45.     long double sum_trap = (f(0.0L) + f(1.0L)) / 2.0L;
  46.  
  47.     for(long long i = 1; i < n; i++) {
  48.         long double x = i * dx;
  49.         sum_trap += f(x);
  50.     }
  51.  
  52.     long double pi_trap = sum_trap * dx;
  53.  
  54.     // ================= WYNIKI =================
  55.     cout << fixed << setprecision(20);
  56.     cout << "Przyblizenie liczby pi:\n";
  57.     cout << "Monte Carlo : " << pi_monte_carlo << endl;
  58.     cout << "Prostokaty  : " << pi_rect << endl;
  59.     cout << "Trapezy     : " << pi_trap << endl;
  60.  
  61.     return 0;
  62. }
Success #stdin #stdout 0.45s 5320KB
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stdin
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Standard input is empty
stdout
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Przyblizenie liczby pi:
Monte Carlo : 3.14081960000000000007
Prostokaty  : 3.14159275358979148888
Trapezy     : 3.14159265358979148883
https://ideone.com/XmGHU5
language:
C++ (gcc 8.3)
created:
16 hours ago
visibility:
public

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