Help with #3 Project Euler

Question

The prime factors of 13195 are 5, 7, 13 and 29.

What is the largest prime factor of the number 600851475143 ?

Code times out before it can get the answer. Any tips to optimise it?

https://code.sololearn.com/cX5lh84cTpUV/?ref=app

Edit 1: Sorry I accidentally deleted part of my code. I fixed it now

Edit 2: Thanks for your help everyone. I solved it :)

Answer 1

I think your code is not good. It gives also time out for 12.

Maybe you should find a better way. In my code I calculated all prime factores.

First search for the first divisor. This is always prime.
number / divisor -> prime? If yes you are done if not the result gets your new number and you repeat this process.

For example:
12
First divisor is 2.
12 / 2 = 6
6
First divisor is 2.
6 / 2 = 3

Prime factors: 2, 2, 3

Answer 2

JOHN PETERSON
It should be: largest = k
instead of: k = largest
There are better (optimized) ways to achieve the goal as Denise Roßberg and fork() have suggested.