Calculate power of a number without built-in pow() public double Power(double x, int n) { if (n == 0) return 1; double half = Power(x, n / 2); if (n % 2 == 0) return half * half; else return n > 0 ?

Short answer: x * half * half : (half * half) / x; Explanation: Uses fast exponentiation (divide and conquer) to calculate x^n in O(log n).

Explain a bit more

x * half * half : (half * half) / x; Explanation: Uses fast exponentiation (divide and conquer) to calculate x^n in O(log n). x * half * half : (half * half) / x; Explanation: Uses fast exponentiation (divide and conquer) to calculate x^n in O(log n). x * half * half : (half * half) / x; Explanation: Uses fast exponentiation (divide and conquer) to calculate x^n in O(log n).

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.