ByteDance

6 problems asked at ByteDance.

Easy (2)

Two Sum (Leetcode 1)

Two Pointers, Arrays

Valid Parentheses (Leetcode 20)

Stack, Strings

Medium (1)

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

Strings, Greedy, Hashing...

Hard (2)

Next Permutation (Leetcode 31)

Arrays, Greedy, Two Pointers

Trapping Rain Water (LC 42)

Two Pointers, Prefix and Suffix Arrays, Stack

Not Specified (1)

Best Time to Buy and Sell Stock

Arrays, DP