// Allison Obourn
// CSE 143 - lecture 14
// Runs the binary search algorithm on a list of TAs.

import java.util.*;

public class Search {
   public static void main(String[] args) {
      ArrayList<String> tas = new ArrayList<String>();
      tas.add("Jacob");
      tas.add("Jessica");
      tas.add("Meredith");
      tas.add("John");
      tas.add("Autumn");
      tas.add("Tyler");
      tas.add("Derek");
      Collections.sort(tas);
      System.out.println(tas);

      int meredith = binarySearch(tas, "Meredith");
      System.out.println(meredith);

      int madison = binarySearch(tas, "Madison");
      System.out.println(madison);
   }

   // Returns the index of target in list using the binary search algorithm.
   // If target is not in list, returns -(insertion point + 1).
   // Pre: list is sorted in ascending order; result is undefined otherwise
   public static int binarySearch(List<String> list, String target) {
      return binarySearch(list, target, 0, list.size() - 1);
   }
   
   // Returns the index of target in list between min and max using the binary
   // search algorithm. If target is not in list, returns -(insertion point + 1).
   // Pre: l is sorted in ascending order; result is undefined otherwise
   private static int binarySearch(List<String> list, String target, int min, int max) {
      int mid = (min + max) / 2;
      
      int compare = target.compareTo(list.get(mid));
      
      if(compare == 0) {      // found the target
         return mid;
      } else if (min > max) { // no names are left
         return - (min + 1);
      } else if (compare > 0) {
         return binarySearch(list, target, mid + 1, max);  // right side
      } else {
         return binarySearch(list, target, min, mid - 1);  // left side
      }
   } 

}