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  1. #include <iostream>
  2. #include <iomanip>
  3. #include <cmath>
  4.  
  5. long double f(long double x) {
  6.     return 4.0L / (1.0L + x * x);
  7. }
  8.  
  9. // Metoda prostokątów (lewostronna)
  10. long double pi_rectangles(long long n) {
  11.     long double dx = 1.0L / n;
  12.     long double sum = 0.0L;
  13.  
  14.     for (long long i = 0; i < n; i++) {
  15.         long double x = i * dx;
  16.         sum += f(x);
  17.     }
  18.  
  19.     return sum * dx;
  20. }
  21.  
  22. // Metoda trapezów
  23. long double pi_trapezoids(long long n) {
  24.     long double dx = 1.0L / n;
  25.     long double sum = (f(0.0L) + f(1.0L)) / 2.0L;
  26.  
  27.     for (long long i = 1; i < n; i++) {
  28.         long double x = i * dx;
  29.         sum += f(x);
  30.     }
  31.  
  32.     return sum * dx;
  33. }
  34.  
  35. int main() {
  36.     long long n;
  37.  
  38.     std::cout << "Podaj liczbe podzialow (np. 100000000): ";
  39.     std::cin >> n;
  40.  
  41.     long double pi_r = pi_rectangles(n);
  42.     long double pi_t = pi_trapezoids(n);
  43.  
  44.     std::cout << std::fixed << std::setprecision(20);
  45.  
  46.     std::cout << "PI (metoda prostokatow): " << pi_r << std::endl;
  47.     std::cout << "PI (metoda trapezow):    " << pi_t << std::endl;
  48.  
  49.     return 0;
  50. }
Success #stdin #stdout 0.98s 5308KB
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stdin
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100000000
stdout
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Podaj liczbe podzialow (np. 100000000): PI (metoda prostokatow): 3.14159266358979394796
PI (metoda trapezow):    3.14159265358979394801
https://ideone.com/yuWnot
language:
C++ (gcc 8.3)
created:
1 day ago
visibility:
public

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