Meta's DSA rounds draw heavily from graphs, trees, hashmap-based techniques, and design-style coding questions like an LRU cache — and several rounds now run with AI-assistance tooling enabled, so interviewers care as much about clear reasoning as the final answer. The three problems below are real, recently reported (2025) Meta questions with full solutions.
Given three separate sorted integer arrays, merge them into a single sorted array with duplicate values removed.
Input: a = [1, 4, 7], b = [2, 4, 6], c = [3, 4, 5]
Output: [1, 2, 3, 4, 5, 6, 7]
The value 4 appears in all three arrays but is written to the result only once.
Design a cache with a fixed capacity that supports O(1) get and put, evicting the least-recently-used entry when full.
Input: cache = LRUCache(2); put(1,1); put(2,2); get(1); put(3,3)
Output: get(1) -> 1, then key 2 is evicted (least recently used)
Given a list of course prerequisites, determine whether all courses can be completed — equivalent to detecting a cycle in a directed graph.
Input: n = 2, prereqs = [[1, 0]]
Output: true
Course 0 has no prerequisite, so course 1 can be taken after it — no cycle.
More DSA questions Meta has asked recently
These topics were reported in verified 2025 Meta loops. Full problem statements, solutions and explanations for these are part of the Placement-Ready PYQ Kit.
9 more verified DSA questions with full solutions in the full Placement-Ready PYQ Kit
Includes every round they were asked in, from the online assessment through onsite loops.