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  1. #include <iostream>
  2. #include <omp.h>
  3. #include <cmath>
  4.  
  5. using namespace std;
  6.  
  7. bool isPrime(int number) {
  8.     if (number <= 1) return false;
  9.     if (number == 2) return true;
  10.     if (number % 2 == 0) return false;
  11.     for (int i = 3; i <= sqrt(number); i += 2) {
  12.         if (number % i == 0) return false;
  13.     }
  14.     return true;
  15. }
  16.  
  17. int main() {
  18.     int I, N;
  19.     cout << "Enter the starting number (I): ";
  20.     cin >> I;
  21.     cout << "Enter the ending number (N): ";
  22.     cin >> N;
  23.  
  24.     int prime_count = 0;
  25.  
  26.     #pragma omp parallel for reduction(+:prime_count)
  27.     for (int i = I; i <= N; ++i) {
  28.         if (isPrime(i)) {
  29.             prime_count++;
  30.         }
  31.     }
  32.  
  33.     cout << "The number of prime numbers between " << I << " and " << N << " is: " << prime_count << endl;
  34.  
  35.     return 0;
  36. }
  37.  
Success #stdin #stdout 0.67s 5292KB
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Standard input is empty
stdout
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Enter the starting number (I): Enter the ending number (N): The number of prime numbers between -952740880 and 22060 is: 2471
https://ideone.com/Q81Mm1
language:
C++14 (gcc 8.3)
created:
3 hours ago
visibility:
public

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