Google's DSA rounds draw heavily from graphs, dynamic programming, intervals, and hashing/array patterns — and interviewers expect you to reason through multiple approaches out loud, not just land on one solution. The three problems below are real, recently reported (2025) Google questions with full solutions.
Given a list of scheduling intervals, merge or select overlapping intervals so the result satisfies a scheduling/allocation constraint (e.g. no two selected meetings overlap).
Input: intervals = [[1,3],[2,6],[8,10],[15,18]]
Output: [[1,6],[8,10],[15,18]]
[1,3] and [2,6] overlap and merge into [1,6]; the rest stay separate.
Given an array of integers, compute the minimum excludant (MEX) — the smallest non-negative integer not present in the array — and be ready to discuss multiple approaches of increasing efficiency.
Input: nums = [3, 4, -1, 1]
Output: 0
Input: nums = [1, 2, 0]
Output: 3
Given the root of a binary tree and two of its nodes, find their lowest common ancestor (LCA) — the deepest node that has both given nodes as descendants (a node can be a descendant of itself).
Input: tree = [3,5,1,6,2,0,8,null,null,7,4], p = 5, q = 1
Output: 3
More DSA questions Google has asked recently
These topics were reported in verified 2025 Google loops. Full problem statements, solutions and explanations for these are part of the Placement-Ready PYQ Kit.
10 more verified DSA questions with full solutions in the full Placement-Ready PYQ Kit
Includes every round they were asked in, from Phone Screen through onsite rounds.