The Blackstone Group Software Engineer interview questions

Applied at a career fair, was asked to come interview with them about 2-3 weeks after. An hour long interview, asked 4 questions. 1) Take a string and turn it to an int. 2) Gave me a SQL data model and wanted me to write a SQL Select statement. Involved a double join. 3) Given 2 arrays, find the unique elements in array 2. 4) Given the class models and a diagram of a binary tree with operators and numbers. Write a function to calculate the value at the root.

Details Met at career fair at school. First round interviews at school. I was interested in software engineering role. First round interview included several basic questions convert a string to an integer, some database questions and one question on expression trees.