Recursive program for prime number

Last Updated : 27 Jan, 2022

Given a number n, check whether it's prime number or not using recursion.
Examples:

Input : n = 11 Output : Yes  Input : n = 15 Output : No

The idea is based on school method to check for prime numbers.

C++

// CPP Program to find whether a Number    // is Prime or Not using Recursion #include <bits/stdc++.h> using namespace std;  // Returns true if n is prime, else // return false. // i is current divisor to check.  bool isPrime(int n, int i = 2) {     // Base cases     if (n <= 2)         return (n == 2) ? true : false;     if (n % i == 0)         return false;     if (i * i > n)         return true;      // Check for next divisor     return isPrime(n, i + 1); }  // Driver Program int main() {     int n = 15;     if (isPrime(n))         cout << "Yes";     else         cout << "No";      return 0; }

Java

// java Program to find whether a Number // is Prime or Not using Recursion import java.util.*;  class GFG {      // Returns true if n is prime, else     // return false.     // i is current divisor to check.     static boolean isPrime(int n, int i)     {          // Base cases         if (n <= 2)             return (n == 2) ? true : false;         if (n % i == 0)             return false;         if (i * i > n)             return true;               // Check for next divisor         return isPrime(n, i + 1);     }          // Driver program to test above function      public static void main(String[] args)     {          int n = 15;          if (isPrime(n, 2))              System.out.println("Yes");         else              System.out.println("No");     } }  // This code is contributed by Sam007.

Python3

# Python 3 Program to find whether # a Number is Prime or Not using # Recursion  # Returns true if n is prime, else # return false. # i is current divisor to check.  def isPrime(n, i = 2):      # Base cases     if (n <= 2):         return True if(n == 2) else False     if (n % i == 0):         return False     if (i * i > n):         return True      # Check for next divisor     return isPrime(n, i + 1)   # Driver Program n = 15 if (isPrime(n)):     print("Yes") else:     print("No")      # This code is contributed by # Smitha Dinesh Semwal

// C# Program to find whether a Number // is Prime or Not using Recursion using System;  class GFG {     // Returns true if n is prime, else     // return false.     // i is current divisor to check.     static bool isPrime(int n, int i)     {          // Base cases         if (n <= 2)             return (n == 2) ? true : false;         if (n % i == 0)             return false;         if (i * i > n)             return true;              // Check for next divisor         return isPrime(n, i + 1);     }               // Driver code     static void Main()     {     int n = 15;          if (isPrime(n, 2))              Console.Write("Yes");         else             Console.Write("No");     }       }  // This code is contributed by Sam007

PHP

<?php // PHP Program to find whether a Number  // is Prime or Not using Recursion  // Returns true if n is prime, else // return false. // i is current divisor to check.  function isPrime($n, $i = 2) {     // Base cases     if ($n <= 2)         return ($n == 2) ? true : false;     if ($n % $i == 0)         return false;     if ($i * $i > $n)         return true;      // Check for next divisor     return isPrime($n, $i + 1); }  // Driver Code $n = 15; if (isPrime($n))     echo("Yes"); else     echo("No");  // This code is contributed by Ajit. ?>

JavaScript

<script>  // JavaScript  program to find whether a Number // is Prime or Not using Recursion      // Returns true if n is prime, else     // return false.     // i is current divisor to check.     function isPrime(n, i)     {            // Base cases         if (n <= 2)             return (n == 2) ? true : false;         if (n % i == 0)             return false;         if (i * i > n)             return true;                 // Check for next divisor         return isPrime(n, i + 1);     }      // Driver code                 let n = 15;            if (isPrime(n, 2))              document.write("Yes");         else              document.write("No");  </script>

Output:

No

Program to find the next prime number

Shahnawaz_Ali

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Recursive program for prime number

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