easy–medium · 15 questions · ~225 min
DS&A · Round 1 foundations (array + hash-map)
Start here. The Round-1 core: two questions, ~30 min each on HackerRank — Q1 a straightforward array, Q2 a medium hash-map. Agoda scores understanding, efficiency, performance, testing, communication — so write tests and narrate out loud.
0 / 15 passed
- 20Contains Duplicatearray · hashset15m
- 01Two Sumarray · hashmap15m
- 22Best Time to Buy and Sell Stockarray · greedy · dynamic-programming15m
- 23Maximum Subarrayarray · dynamic-programming · divide-and-conquer15m
- 24Move Zeroesarray · two-pointers15m
- 26Missing Numberarray · math · bit-manipulation15m
- 27Merge Sorted Arrayarray · two-pointers · sorting15m
- 28Sort Colorsarray · two-pointers · sorting15m
- 25Valid Palindromestring · two-pointers15m
- 21Valid Anagramstring · hashmap · sorting15m
- 11Group Anagramsarray · hashmap · string15m
- 07Top K Frequent Elementsheap · bucket-sort · hashmap15m
- 31Top Users by Spending (bookings)array · hashmap · sorting · heap15m
- 29Subarray Sum Equals Karray · hashmap · prefix-sum15m
- 30Longest Consecutive Sequencearray · hashset · union-find15m