InsideView Software Development Engineer In Test interview questions

I was called for the interview.The receiving was very warm.Even the company had a good ambience.We then had a programming test.The paper had the following 5 questions: 1.in a string every opening brace should have a closing brace.Strings which satisfy this criteria are valid and those which don't are invalis.Write a code to test if a string is valid . 2.given an array of characters.Write a code to replace every space in a array with %20. 3.Given 32 numbers.What is the minimum no of comparisions to find the 2nd smallest among them(puzzle) 4.Write test scenarios for testing the functionality of searching friends or friends of friends in Facebook API. 5.Given an array of integers .write a code to return the an interval which covers maximum numbers in the array.For eg: For {1,2,7,,3,6,4,9} it should return [1,4]. Time for the written tewst was 90 min though some grace time is given.I couldn't clear the test.