Problem 3 Largest prime factor (factorization factor) __problem

largest prime factor Problem 3

The prime factors of 13195 are 5, 7, and 29.

What is the largest prime factor of the number 600851475143?

Answer:

6857

Exercises

Let the given number is n and let k = 2, 3, 4, 5, .... For all k, if it is a factor of n then we divide n by K and completely divide out each k before moving to the next K. It can be seen then K is a factor it'll necessarily be prime, as all smaller factors the have been removed, andthe FINA L result of the This process would be n = 1.

Code:

#include <bits/stdc++.h>
using namespace std;
Long Long num = 600851475143ll;
int main ()
{
	long i, max = 1;
	for (i = 2; I * i <= num; i++)
	{
		if (num% i = = 0)
		{
			max = i;
			while (num% i = = 0) num/= i;
		}
 	 if (num > 1) max = num;
	}		
	cout<<max<<endl;
	return 0;
}