Java Program for Find largest prime factor of a number
Given a positive integer \’n\'( 1 <= n <= 1015). Find the largest prime factor of a number.
Input: 6 Output: 3 Explanation Prime factor of 6 are- 2, 3 Largest of them is \'3\' Input: 15 Output: 5
Java
// Java Program to find largest// prime factor of numberimport java.io.*;import java.util.*; class GFG { // function to find largest prime factorstatic long maxPrimeFactors( long n){ // Initialize the maximum prime // factor variable with the // lowest one long maxPrime = -1; // Print the number of 2s // that divide n while (n % 2 == 0) { maxPrime = 2; // equivalent to n /= 2 n >>= 1; } // n must be odd at this point, // thus skip the even numbers // and iterate only for odd // integers for (int i = 3; i <= Math.sqrt(n); i += 2) { while (n % i == 0) { maxPrime = i; n = n / i; } } // This condition is to handle // the case when n is a prime // number greater than 2 if (n > 2) maxPrime = n; return maxPrime;} // Driver codepublic static void main(String[] args){ Long n = 15l; System.out.println(maxPrimeFactors(n)); n = 25698751364526l; System.out.println(maxPrimeFactors(n));}} // This code is contributed by Gitanjali |
Output:
5 328513
Time complexity: 
Auxiliary space: 
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