Zoho

9 problems asked at Zoho.

Easy (2)

Two Sum (Leetcode 1)

Two Pointers, Arrays

Valid Parentheses (Leetcode 20)

Stack, Strings

Medium (3)

Gas Station (Leetcode 134)

Arrays, Greedy, Prefix Sum

Longest Substring Without Repeating Characters (leetcode 3)

Sliding Window, Strings, Hashing

Remove Duplicate Letters / Smallest Subsequence of Distinct Characters (Leetcode 316 / 1081)

Strings, Greedy, Hashing...

Hard (3)

Maximal Rectangle (Leetcode 85) (largest rectangle with all 1's)

Matrix, Stack

N-Queens (Leetcode 51 & 52)

Backtracking, Maths, Recursion...

Trapping Rain Water (LC 42)

Two Pointers, Prefix and Suffix Arrays, Stack

Not Specified (1)

Best Time to Buy and Sell Stock

Arrays, DP