Activision Coding Interview Questions
25 Activision coding interview problems with full optimal solutions — 15 easy, 7 medium, 3 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Activision interviewer values, and a FAQ section.
Showing 15 problems of 25
- #1easyfoundational
1. Two Sum
Find two indices in an array whose values sum to a target — a warm-up Activision uses to gauge hash-map fluency before diving into matchmaking logic.
- #2easyfoundational
2. Valid Parentheses
Decide whether a string of brackets is balanced — Activision uses it to gauge stack fluency relevant to chat command parsing and config validation.
- #3easyfoundational
3. Merge Two Sorted Lists
Merge two sorted linked lists into one — Activision uses it to gauge pointer manipulation relevant to merging player feeds or sorted match logs.
- #4easyfoundational
4. Remove Duplicates from Sorted Array
Remove duplicates in-place from a sorted array — Activision uses this to test two-pointer fluency on leaderboard scrubbing.
- #5easyfoundational
5. Remove Element
Remove all instances of a value in-place — Activision uses it to gauge how you handle compaction of banned-player records.
- #6easyfoundational
6. Search Insert Position
Find the insertion index for a target in a sorted array — Activision uses this to verify binary search fluency on sorted skill-rating tables.
- #7easyfoundational
7. Plus One
Increment a non-negative integer represented as a digit array — Activision uses this to test edge-case discipline relevant to versioned save files.
- #8easyfoundational
8. Merge Sorted Array
Merge nums2 into nums1 in-place with both arrays already sorted — Activision uses this to verify reverse-pointer fluency on session telemetry merges.
- #9easyfoundational
9. Binary Tree Inorder Traversal
Return the inorder traversal of a binary tree — Activision asks this to verify recursion-versus-stack fluency that maps to scene-graph traversal.
- #10easyfoundational
10. Same Tree
Decide whether two binary trees are structurally identical — Activision uses this to test recursive equality checks akin to scene-graph diffing.
- #11easyfoundational
11. Symmetric Tree
Determine whether a binary tree is a mirror of itself — Activision uses this to gauge recursion fluency before pivoting to matchmaking-bracket trees.
- #12easyfoundational
12. Maximum Depth of Binary Tree
Return the depth of a binary tree — Activision uses this to confirm DFS basics before asking about leaderboard tree depth for season-rank tiers.
- #13easyfoundational
13. Best Time to Buy and Sell Stock
Find the maximum profit from one buy/sell pair — Activision uses this to gauge single-pass thinking before pivoting to leaderboard rating-delta problems.
- #14easyfoundational
14. Single Number
Find the element that appears once when every other element appears twice — Activision uses this to gauge bit-manipulation fluency before anti-cheat telemetry dedup questions.
- #15easyfoundational
15. Linked List Cycle
Detect whether a linked list contains a cycle — Activision uses this to gauge two-pointer instincts before chat-moderation graph cycle questions.