JAVA

Let M be an nn matrix, consisting of nn1 'a'-s and a single 'b'. In one step, you can swap any two adjacent cells of M. Write a program that inputs natural odd number n, and then uses a recursive method to "read" M (that is represented as n lines, each containing n characters separated by a single space) and calculate the minimum number of steps needed to relocate the only ' b ' to the center of M. The program should use minimum number of primitive operations and method calls. What is a tight upper-bound on the running time of this method? What is the worst case complexity? When do we encounter the worst case? What is the space complexity