Oracle's DSA rounds lean on classic data-structure fundamentals — trees, linked lists, strings, and heaps — often paired with a follow-up push toward making the design extensible or production- ready, rather than stopping once the base case works. The problems below are real, verified Oracle questions with full solutions.
Write a function that converts an integer to its Roman numeral representation. Once working, the interviewer pushes further: how would you change the symbol-value mapping so the same converter could support a different or future numeral system without rewriting the core logic?
Input: num = 1994
Output: "MCMXCIV"
Input: num = 58
Output: "LVIII"
Given two strings, determine whether one is an anagram of the other — but you are not allowed to sort either string as part of your solution.
Input: s1 = "listen", s2 = "silent"
Output: true
Input: s1 = "rat", s2 = "car"
Output: false
More DSA topics Oracle has asked recently
These topics reflect patterns reported across recent Oracle loops. Full problem statements, solutions and explanations for these are part of the Placement-Ready PYQ Kit.
8 more DSA questions with full solutions in the full Placement-Ready PYQ Kit
Includes the exact round each pattern showed up in, from the screening round through the loop.