**Question**\nGiven an array of size `n` containing numbers in the range of `long` data type, find out all the duplicates in the array.\n\n**Sample Input 0**\n`[2, 3011, 4, 2, 1, 5, 3011, 8000]`\nOutput should be 2 and 3011.\n\nIs it possible to find the frequency of repeating elements? How if possible?\n\n\nExpected time - O(n)\nExpected space - O(1)\n\nSimilar problems\nhttps://leetcode.com/problems/find-all-duplicates-in-an-array/\n\n\n\nP.S. - I solved in 2 ways.\n1st method - O(n) time complexity and O(n) space complexity\n2nd method - O(nlogn) time complexity and O(1) space complexity\nThese complexities were not able to satisfy the interviewer. It needed to be more optimized.

Question\nGiven an array of size n containing numbers in the range of long data type, find out all the duplicates in the array.\n\nSample Input 0\n[2, 3011, 4, 