Sunmerge Systems interview questions

Accepted Offer Interview 1st Interview round: 1) Function for creating and inserting elements into a Binary Search Tree. 2) Function for linear search that returns the position of the element found. After these were mostly questions from databases and I don't remember all of it. These are the ones I remember- 3) Difference between Primary key and the Unique constraint. 4) What is Join? Different types of Join? Explain all of them. 2nd Interview round: 1) What is dynamic programming? Give an example. 2) Given the fact that there is a loop in a linked list, how do you identify where the loop is? 3) Given an array A[], replace all '*' with three '-' in the array. For eg: Input Array : [1 2 * 3 4 * 5] Output Array : [1 2 - - - 3 4 - - - 5] 4) There is a lizard at one corner of a cubic room of side, 1 unit. At the corner diagonally opposite to this, there's a cockroach that is present.