Dado un número entero N , la tarea es imprimir todos los números primos multiplicativos ≤ N .
Los números primos multiplicativos son los números primos tales que el producto de sus dígitos también es número primo. Por ejemplo; 2, 3, 7, 13, 17, …
Ejemplos:
Entrada: N = 10
Salida: 2 3 5 7
Entrada: N = 3
Salida: 2 3
Enfoque: Utilizando la criba de Eratóstenes , compruebe si todos los números primos ≤ N son números primos multiplicativos, es decir, el producto de sus dígitos también es un número primo. En caso afirmativo, imprima esos números primos multiplicativos.
A continuación se muestra la implementación del enfoque anterior:
C++
// C++ implementation of the approach #include <bits/stdc++.h> using namespace std; // Function to return the digit product of n int digitProduct(int n) { int prod = 1; while (n) { prod = prod * (n % 10); n = n / 10; } return prod; } // Function to print all multiplicative primes <= n void printMultiplicativePrimes(int n) { // Create a boolean array "prime[0..n+1]". A // value in prime[i] will finally be false // if i is Not a prime, else true. bool prime[n + 1]; memset(prime, true, sizeof(prime)); prime[0] = prime[1] = false; for (int p = 2; p * p <= n; p++) { // If prime[p] is not changed, then // it is a prime if (prime[p]) { // Update all multiples of p for (int i = p * 2; i <= n; i += p) prime[i] = false; } } for (int i = 2; i <= n; i++) { // If i is prime and its digit sum is also prime // i.e. i is a multiplicative prime if (prime[i] && prime[digitProduct(i)]) cout << i << " "; } } // Driver code int main() { int n = 10; printMultiplicativePrimes(n); }
Java
// Java implementation of the approach import java.io.*; class GFG { // Function to return the digit product of n static int digitProduct(int n) { int prod = 1; while (n > 0) { prod = prod * (n % 10); n = n / 10; } return prod; } // Function to print all multiplicative primes <= n static void printMultiplicativePrimes(int n) { // Create a boolean array "prime[0..n+1]". A // value in prime[i] will finally be false // if i is Not a prime, else true. boolean prime[] = new boolean[n + 1 ]; for(int i = 0; i <= n; i++) prime[i] = true; prime[0] = prime[1] = false; for (int p = 2; p * p <= n; p++) { // If prime[p] is not changed, then // it is a prime if (prime[p]) { // Update all multiples of p for (int i = p * 2; i <= n; i += p) prime[i] = false; } } for (int i = 2; i <= n; i++) { // If i is prime and its digit sum is also prime // i.e. i is a multiplicative prime if (prime[i] && prime[digitProduct(i)]) System.out.print( i + " "); } } // Driver code public static void main (String[] args) { int n = 10; printMultiplicativePrimes(n); } } // This code is contributed by shs..
Python3
# Python 3 implementation of the approach from math import sqrt # Function to return the digit product of n def digitProduct(n): prod = 1 while (n): prod = prod * (n % 10) n = int(n / 10) return prod # Function to print all multiplicative # primes <= n def printMultiplicativePrimes(n): # Create a boolean array "prime[0..n+1]". # A value in prime[i] will finally be # false if i is Not a prime, else true. prime = [True for i in range(n + 1)] prime[0] = prime[1] = False for p in range(2, int(sqrt(n)) + 1, 1): # If prime[p] is not changed, # then it is a prime if (prime[p]): # Update all multiples of p for i in range(p * 2, n + 1, p): prime[i] = False for i in range(2, n + 1, 1): # If i is prime and its digit sum # is also prime i.e. i is a # multiplicative prime if (prime[i] and prime[digitProduct(i)]): print(i, end = " ") # Driver code if __name__ == '__main__': n = 10 printMultiplicativePrimes(n) # This code is contributed by # Surendra_Gangwar
C#
// C# implementation of the approach class GFG { // Function to return the digit product of n static int digitProduct(int n) { int prod = 1; while (n > 0) { prod = prod * (n % 10); n = n / 10; } return prod; } // Function to print all multiplicative primes <= n static void printMultiplicativePrimes(int n) { // Create a boolean array "prime[0..n+1]". A // value in prime[i] will finally be false // if i is Not a prime, else true. bool[] prime = new bool[n + 1 ]; for(int i = 0; i <= n; i++) prime[i] = true; prime[0] = prime[1] = false; for (int p = 2; p * p <= n; p++) { // If prime[p] is not changed, then // it is a prime if (prime[p]) { // Update all multiples of p for (int i = p * 2; i <= n; i += p) prime[i] = false; } } for (int i = 2; i <= n; i++) { // If i is prime and its digit sum is also prime // i.e. i is a multiplicative prime if (prime[i] && prime[digitProduct(i)]) System.Console.Write( i + " "); } } // Driver code static void Main() { int n = 10; printMultiplicativePrimes(n); } } // This code is contributed by chandan_jnu
PHP
<?php // PHP implementation of the approach // Function to return the digit product of n function digitProduct($n) { $prod = 1; while ($n) { $prod = $prod * ($n % 10); $n = floor($n / 10); } return $prod; } // Function to print all multiplicative // primes <= n function printMultiplicativePrimes($n) { // Create a boolean array "prime[0..n+1]". // A value in prime[i] will finally be // false if i is Not a prime, else true. $prime = array_fill(0, $n + 1, true); $prime[0] = $prime[1] = false; for ($p = 2; $p * $p <= $n; $p++) { // If prime[p] is not changed, then // it is a prime if ($prime[$p]) { // Update all multiples of p for ($i = $p * 2; $i <= $n; $i += $p) $prime[$i] = false; } } for ($i = 2; $i <= $n; $i++) { // If i is prime and its digit sum is also // prime i.e. i is a multiplicative prime if ($prime[$i] && $prime[digitProduct($i)]) echo $i, " "; } } // Driver code $n = 10; printMultiplicativePrimes($n); // This code is contributed by Ryuga. ?>
Javascript
<script> // Javascript implementation of the approach // Function to return the digit product of n function digitProduct(n) { let prod = 1; while (n > 0) { prod = prod * (n % 10); n = Math.floor(n / 10); } return prod; } // Function to print all // multiplicative primes <= n function printMultiplicativePrimes(n) { // Create a boolean array "prime[0..n+1]". A // value in prime[i] will finally be false // if i is Not a prime, else true. let prime = new Array(n + 1); for(let i = 0; i <= n; i++) prime[i] = true; prime[0] = prime[1] = false; for (let p = 2; p * p <= n; p++) { // If prime[p] is not changed, then // it is a prime if (prime[p]) { // Update all multiples of p for (let i = p * 2; i <= n; i += p) prime[i] = false; } } for (let i = 2; i <= n; i++) { // If i is prime and its digit sum is also prime // i.e. i is a multiplicative prime if (prime[i] && prime[digitProduct(i)]) document.write( i + " "); } } // Driver code let n = 10; printMultiplicativePrimes(n); // This code is contributed by unknown2108 </script>
2 3 5 7
Complejidad del tiempo: O(n 3/2 )
Espacio Auxiliar: O(n)
Publicación traducida automáticamente
Artículo escrito por mohit kumar 29 y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA