Recursive function

Question

Hi.
I'm doing a programming project for school which involves a merge sort. I copied the code directly from a book, only the recursion isn't working. Throughout the year we've been doing work with recursion and it's been rather mean to me. My teacher has no clue what the problem is, but every time i try to make a recursive loop i have to jury rig it to work. For example, if i make a pathfinder, i have to tell it manually to backtrack after it finishes a "level" of recursion, rahter than just returning to the previous environment automatically. I've tried various IDEs (i use primarily Eclipse and Textpad) and nothing seems to work. Currently what i'm dealing with is as follows:
     public static void domergesort(board[] v, int st, int end)
          board[] tmp=new board[1];
          Vector vect=new Vector();
          if(st<end)
               int mid=(st+end)/2;
               System.out.println(end);
               domergesort(v,st,mid);
               System.out.println(end);
               domergesort(v,mid+1,end);
               merge(v,st,mid,end);
     }i put System.outs to see how far it gets through the code in the if-statement (cuz i knew it wasn't getting to merge()) and it didn't get past the first call of domergesort()
I'm guessing this problem is an extension of what i saw before: each time domergesort is called, the value for end is replaced by that of mid, and when end decreases to 0, the Java passes over the if statement, but when it backtracks a level, the value of end doesn't return to its previous value.
any ideas???

Answer 1

sorry.
solved my problem. turns out i was dumb and put the printing function inside the recursive loop so it tried to print the sorted list before it was done sorting, which is what screwed things up
but the thing about passing having to manually-reset things (like Vectors and arrays) is still up in the air