/* File: Test2.java -- March 2018 */
package l03;

/**
 * Tests whether a number is a perfect square using a fairly efficient
 * algorithm.
 *
 * @author Michael Albert
 *
 */
 
public class Test2 implements SquareTest{

  long loops = 0;
  long n;
  
  public boolean isSquare(long n) {
    this.n = n;
    long low = 1, high = 1, mid = 1;
      loops = 0;
      long current = 1;
      while (current*current < n) {
         loops += 1;
         low = current;
         current *=2 ;
      }

      high = current;
      if (high*high == n) return true;
      while (high - low >= 2) {
         loops += 1;
         mid = (high+low)/2;
         long m2 = mid*mid;
         if (m2 == n) {
            return true;
         }
         else if (m2 < n) {
            low = mid;
         }
         else {
            high = mid;
         }
      }
      return false;
    
  }
  
  public String report() {
    return "A2 loops for input " + n + " was " + loops;
  }
  
  public static void main(String[] args) {
    long n = Long.parseLong(args[0]);
    SquareTest test = new Test2();
    System.out.println(test.isSquare(n));
    System.out.println(test.report());
  
  }
}