"Junior developers are often responsible for writing the more monotonous and simple code required by senior members of the development team. Because of this, interviews will be designed to test your knowledge of the fundamentals of Java so be prepared to answer technical questions that you likely came across in college. Data structures and algorithms will be heavily emphasised. A bachelor's degree or equivalent work experience is required. "
Given an array of N integers, find the missing integer.
Iterate through array, keeping a sum of the values. Subtract the final answer from n*(n-1)/2
the answer is subtract the sum from n*(n+1)/2
Is that a well-known algorithm? I don't know how you could ever have figured that out. I would have sorted the array and iterated until I got to the missing integer.