Find Largest Prime Factor of a Number?

Short answer: long LargestPrimeFactor(long n) {

Example code

long maxPrime = -1; while (n % 2 == 0) {
maxPrime = 2;
n /= 2;
}
for (long i = 3; i * i <= n; i += 2)
{ while (n % i == 0) {
maxPrime = i;
n /= i;
}
}
if (n > 2) maxPrime = n;
return maxPrime;
} Follow on: Explanation: Divide out factors of 2, then test odd factors; leftover > 2 is prime. Miscellaneous Problems

Real-world example (ShopNest)

In coding rounds, state complexity aloud, write a clear ShopNest-flavored example (orders, carts), then handle edge cases (empty list, null, overflow).

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.