Uber

13 problems asked at Uber.

Easy (3)

Top K Frequent Elements (Leetcode 347)

Arrays, Hashing, Heap...

Two Sum (Leetcode 1)

Two Pointers, Arrays

Valid Parentheses (Leetcode 20)

Stack, Strings

Medium (3)

Group Anagrams (Leetcode 49)

Arrays, Strings, Sorting...

Longest Substring Without Repeating Characters (leetcode 3)

Sliding Window, Strings, Hashing

Min Stack (Leetcode 155)

Stack

Hard (6)

First Missing Positive (LC 41)

Arrays, Sorting, Hashing

Largest Rectangle in Histogram (leetcode 84)

Arrays, Stack

Next Permutation (Leetcode 31)

Arrays, Greedy, Two Pointers

Repeating Element (Cycle + Expected Sum appr.)

Arrays, Two Pointers, Linked Lists

Shortest Palindrome (Leetcode 214)

Strings, Greedy

Trapping Rain Water (LC 42)

Two Pointers, Prefix and Suffix Arrays, Stack

Not Specified (1)

Best Time to Buy and Sell Stock

Arrays, DP