Uber Coding Interview Questions
20 Uber coding interview problems with full optimal solutions — 3 easy, 8 medium, 9 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Uber interviewer values, and a FAQ section.
Showing 4 problems of 20
- #23hardfrequently asked
23. Merge k Sorted Lists
Merge k sorted linked lists into one sorted list. Uber asks this to test whether you reach for the min-heap (or divide-and-conquer pairwise merge) and can articulate why N log k beats N log N.
3 free resourcesSolve → - #42hardfrequently asked
42. Trapping Rain Water
Given an elevation map of bar heights, compute how much water can be trapped after rain. Uber asks this to test whether you reach for the two-pointer O(1)-space solution after seeing the prefix-max O(n)-space one.
3 free resourcesSolve → - #76hardfrequently asked
76. Minimum Window Substring
Find the smallest substring of s that contains every char of t (with multiplicities). Uber asks this as the canonical 'two-pointer plus need/have' sliding-window template — they want to see the formed-count trick.
3 free resourcesSolve → - #127hardfrequently asked
127. Word Ladder
Given beginWord, endWord, and a word list, find the length of the shortest transformation sequence where each step changes one letter and lands in the list. Uber candidates report this hard BFS staple because it tests graphs that are never materialized — the wildcard-bucket trick (h*t, *ot) collapses neighbor discovery from 26 probes per letter into one dictionary lookup, and recognizing that is the difference between passing and timing out.
3 free resourcesSolve →
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