// This program demonstrates some basic usage of booleans types
//   and values. Notice the use of good "Boolean zen" and the
//   "innocent until proven guilty" pattern in the flipCoin
//   method.
import java.util.*;

public class CoinFlips {
   public static void main(String[] args) {
      int count = 0;
      for (int i = 0; i < 1000; i++) {
         boolean result = flipCoin(5);
//          bad Boolean Zen - DON'T DO THIS!!
//          if (result == true) {
//             count ++;
//          }
         if (result) {
            count++;
         }
      }
      // analysis
   }
   
   // Write a method flipCoin that takes a single integer parameter
   // and simulates flipping a coin at most that many times. The 
   // method should return true if at least one flip comes up "heads" 
   // and false if all flips come up "tails."
   //
   // int numTries - the maximum number of times to flip
   public static boolean flipCoin(int numTries) {
      Random rand = new Random();
      for (int i = 1; i <= numTries; i++) {
         int flip = rand.nextInt(2);      // 0 = heads, 1 = tails
         if (flip == 0) {
            return true;
         }
      }
      return false;     // assert: NEVER have flipped heads
   }
}