LeetCode : o(n) time complexity and constant space solution for Finding All Duplicates in an Array

I find solving LeetCode challenges a great way to enhance problem solving skills, even if you are highly experienced software engineer you should try to do couple of problems a week, it is great way to boost your coding skills and is really amazing... Initially you may find it difficult, but as you keep solving the challenges, it is fun...I will try to create LeetCode challenge solutions video in between along with my other Tech video . To begin with I am starting with a very simple problem of finding duplicates in an array with o(n) time complexity and constant space.