First Duplicate in Array - Google Coding Interview Question - Extreme Programmer

#ArraysInJava #JavaTutorials #OnlineTraining This question made its appearance in many exams like - TCS-Ignite, TCS-Ninja, Codeblazer, Code gladiator, Google Preselection, Amazon Preselection and many more. ------------------------------------------------------------------------------------------------------------------------------------- Concept: Find the first duplicate number for which the second occurrence has the minimal index. In other words, if there are more than 1 duplicated numbers, return the number for which the second occurrence has a smaller index than the second occurrence of the other number does. If there are no such elements, return -1 For a = [2, 1, 3, 5, 3, 2], the output should be firstDuplicate(a) = 3. There are 2 duplicates: numbers 2 and 3. The second occurrence of 3 has a smaller index than the second occurrence of 2 does, so the answer is 3. ------------------------------------------------------------------------------------------------------------------------------------- If you have any such doubt full question please let me know in the comment section below. Don't forget to like, share and subscribe. Thankyou!