Yandex

7 problems asked at Yandex.

Easy (3)

Implement Queue using Stacks (LeetCode 232)

Stack, Queue

Two Sum (Leetcode 1)

Two Pointers, Arrays

Valid Parentheses (Leetcode 20)

Stack, Strings

Medium (2)

Longest Substring Without Repeating Characters (leetcode 3)

Sliding Window, Strings, Hashing

Min Stack (Leetcode 155)

Stack

Hard (2)

Postfix to Infix & Evaluation of Postfix (Leetcode 150)

Stack

Trapping Rain Water (LC 42)

Two Pointers, Prefix and Suffix Arrays, Stack