Python-এ array-type interview problem সাধারণত list নিয়ে হয়।

Common patterns:

Hash Map
Two Pointers
Sliding Window
Prefix Sum
Sorting
Binary Search

Example: Two Sum

Input:

nums = [2, 7, 11, 15]
target = 9

Need:

2 + 7 = 9

Naive solution:

Every pair check
O(n²)

Better:

def two_sum(nums, target):
    seen = {}

    for i, x in enumerate(nums):
        need = target - x

        if need in seen:
            return [seen[need], i]

        seen[x] = i

Time:

$$O\left. (n) \right.$$

Space:

$$O\left. (n) \right.$$