Quicksort?

Short answer: void QuickSort(int[] arr, int low, int high) {

Example code

if (low < high) Follow on: {
int pi = Partition(arr, low, high); QuickSort(arr, low, pi - 1); QuickSort(arr, pi + 1, high); }
}
int Partition(int[] arr, int low, int high)
{
int pivot = arr[high];
int i = low - 1;
for (int j = low; j < high; j++)
{
if (arr[j] < pivot)
{ i++; (arr[i], arr[j]) = (arr[j], arr[i]);
}
}
(arr[i + 1], arr[high]) = (arr[high], arr[i + 1]);
return i + 1;
} Explanation: Choose last element as pivot, partition array so left < pivot < right, recursively sort subarrays.

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.