Dado un entero positivo n, la tarea es verificar si es un número primo de Chen. Si el número dado es un número Chen Prime, imprima ‘SÍ’; de lo contrario, imprima ‘NO’.
Número primo de Chen : en matemáticas, un número primo ‘p’ se denomina número primo de Chen , si ‘p+2’ es un número primo o un número semiprimo.
Un número semiprimo es el producto de dos números primos.
Los primeros números primos de Chen son:
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 47, 53, 59, 67, 71, 83, 89, 101
Ejemplos:
Input : 11 Output: YES Explanation: 11 is prime number and 11+2 (i.e 13 is also prime number) Input : 7 Output: YES Explanation: 7 is prime number and 7+2 ( i.e 9 ) is a semi prime number
requisito previo :
Acercarse:
- Comprueba si el número dado – ‘n’ es primo o no.
- Si n es un número primo:
- Comprobar si n+2 es primo o semiprimo
- Imprime ‘SÍ’ si n+2 es un número primo o un número semiprimo
- De lo contrario, escriba ‘NO’
- Si n no es un número primo, imprima ‘NO’.
A continuación se muestra la implementación de la idea anterior.
CPP
// CPP program to check // Chen prime number #include <bits/stdc++.h> using namespace std; // Utility function to check whether // number is semiprime or not int isSemiprime(int num) { int cnt = 0; for (int i = 2; cnt < 2 && i * i <= num; ++i) while (num % i == 0) num /= i, ++cnt; // Increment count // of prime numbers // If number is greater than 1, add it to // the count variable as it indicates the // number remain is prime number if (num > 1) ++cnt; // Return '1' if count is equal to '2' else // return '0' return cnt == 2; } // Utility function to check whether // the given number is prime or not bool isPrime(int n) { // Corner cases if (n <= 1) return false; if (n <= 3) return true; // This is checked so that we can skip // middle five numbers in below loop if (n % 2 == 0 || n % 3 == 0) return false; for (int i = 5; i * i <= n; i = i + 6) { if (n % i == 0 || n % (i + 2) == 0) { return false; } } return true; } // Function to check Chen prime number bool isChenPrime(int n) { if (isPrime(n) && (isSemiprime(n + 2) || isPrime(n + 2))) return true; else return false; } // Driver code int main() { int n = 7; if (isChenPrime(n)) cout << "YES"; else cout << "NO"; return 0; }
Java
// JAVA program to check // Chen Prime number class GFG { // Utility function to check // if the given number is semi-prime or not static boolean isSemiPrime(int num) { int cnt = 0; for (int i = 2; cnt < 2 && i * i <= num; ++i) while (num % i == 0) { num /= i; // Increment count // of prime numbers ++cnt; } // If number is greater than 1, // add it to the count variable // as it indicates the number // remain is prime number if (num > 1) ++cnt; // Return '1' if count is equal // to '2' else return '0' return cnt == 2 ? true : false; } // Function to check if a number is prime or not static boolean isPrime(int n) { // Corner cases if (n <= 1) return false; if (n <= 3) return true; // This is checked so that we can skip // middle five numbers in below loop if (n % 2 == 0 || n % 3 == 0) return false; for (int i = 5; i * i <= n; i = i + 6) { if (n % i == 0 || n % (i + 2) == 0) { return false; } } return true; } // Function to check chen prime number static boolean isChenPrime(int n) { if (isPrime(n) && (isSemiPrime(n + 2) || isPrime(n + 2))) return true; else return false; } // Driver code public static void main(String[] args) { int n = 7; if (isChenPrime(n)) System.out.println("YES"); else System.out.println("NO"); } }
C#
// C# program to check // Chen Prime number using System; class GFG { // Utility function to check // if the given number is semi-prime or not static bool isSemiPrime(int num) { int cnt = 0; for (int i = 2; cnt < 2 && i * i <= num; ++i) while (num % i == 0) { num /= i; // Increment count // of prime numbers ++cnt; } // If number is greater than 1, // add it to the count variable // as it indicates the number // remain is prime number if (num > 1) ++cnt; // Return '1' if count is equal // to '2' else return '0' return cnt == 2 ? true : false; } // Function to check if a number is prime or not static bool isPrime(int n) { // Corner cases if (n <= 1) return false; if (n <= 3) return true; // This is checked so that we can skip // middle five numbers in below loop if (n % 2 == 0 || n % 3 == 0) return false; for (int i = 5; i * i <= n; i = i + 6) { if (n % i == 0 || n % (i + 2) == 0) { return false; } } return true; } // Function to check chen prime number static bool isChenPrime(int n) { if (isPrime(n) && (isSemiPrime(n + 2) || isPrime(n + 2))) return true; else return false; } // Driver code public static void Main() { int n = 7; if (isChenPrime(n)) Console.WriteLine("YES"); else Console.WriteLine("NO"); } }
Python3
# Python3 program to check # Chen Prime number import math # Utility function to Check # Semi-prime number def isSemiPrime(num): cnt = 0 for i in range(2, int(math.sqrt(num)) + 1): while num % i == 0: num /= i cnt += 1 # Increment count # of prime number # If count is greater than 2, # break loop if cnt >= 2: break # If number is greater than 1, add it to # the count variable as it indicates the # number remain is prime number if(num > 1): cnt += 1 # Return '1' if count is equal to '2' else # return '0' return cnt == 2 # Utility function to check # if a number is prime or not def isPrime(n) : # Corner cases if (n <= 1) : return False if (n <= 3) : return True # This is checked so that we can skip # middle five numbers in below loop if (n % 2 == 0 or n % 3 == 0) : return False i = 5 while(i * i <= n) : if (n % i == 0 or n % (i + 2) == 0) : return False i = i + 6 return True # Function to check if the # Given number is Chen prime number or not def isChenPrime( n): if(isPrime(n) and (isSemiPrime(n + 2) or isPrime(n + 2))): return True else: return False # Driver code n = 7 if(isChenPrime(n)): print("YES"); else: print("NO");
Javascript
<script> // Javascript program to check // Chen prime number // Utility function to check whether // number is semiprime or not function isSemiprime(num) { var cnt = 0; for (var i = 2; cnt < 2 && i * i <= num; ++i) while (num % i == 0) num /= i, ++cnt; // Increment count // of prime numbers // If number is greater than 1, add it to // the count variable as it indicates the // number remain is prime number if (num > 1) ++cnt; // Return '1' if count is equal to '2' else // return '0' return cnt == 2; } // Utility function to check whether // the given number is prime or not function isPrime(n) { // Corner cases if (n <= 1) return false; if (n <= 3) return true; // This is checked so that we can skip // middle five numbers in below loop if (n % 2 == 0 || n % 3 == 0) return false; for (var i = 5; i * i <= n; i = i + 6) { if (n % i == 0 || n % (i + 2) == 0) { return false; } } return true; } // Function to check Chen prime number function isChenPrime(n) { if (isPrime(n) && (isSemiprime(n + 2) || isPrime(n + 2))) return true; else return false; } // Driver code var n = 7; if (isChenPrime(n)) document.write( "YES"); else document.write( "NO"); // This code is contributed by noob2000. </script>
Producción:
YES