// Connor Moore, CSE 143
// Runs the binary search algorithm on a list of TAs.

import java.util.*;

public class Search {
  public static void main(String[] args) {
    List<String> tas = new ArrayList<String>();
    tas.add("Alan");
    tas.add("Halden");
    tas.add("Shobhit");
    tas.add("Tanvi");
    tas.add("Cody");
    tas.add("Melissa");
    tas.add("Chloe");
    System.out.println(tas);
    Collections.sort(tas);
    System.out.println(tas);

    int cody = binarySearch(tas, "Cody");
    System.out.println(cody);

    int connor = binarySearch(tas, "Connor");
    System.out.println(connor);
  }

  // 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) {
    // notice the exclusive upper bound
    return binarySearch(list, target, 0, list.size());
  }

  // Returns the index of target in l between min and max using the binary
  // search algorithm. If target is not in l, 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) {
    if (min >= max) {
      return -(min + 1);
    } else {
      // split the list in 2
      int mid = (max + min) / 2;
      if (target.compareTo(list.get(mid)) == 0) {
        return mid;
      } else if (target.compareTo(list.get(mid)) < 0) {
        // search left half if ... target < "midpoint"
        return binarySearch(list, target, min, mid);
      } else {
        // otherwise search right half
        return binarySearch(list, target, mid + 1, max);
      }
    }
  }
}