RecursionGuessNumberGameCode

/*Doug Bennett                                              */
/*12/05/2017                                                */
/*This program is a guessing game designed to demonstrate   */
/*how recursive programming works                           */
/************************************************************/

import java.util.Scanner;

public class RecursionGuessNumberGame {
   public static void guessNumber(int lowNum, int highNum) {
      Scanner scnr = new Scanner(System.in);
      int midNum = 0;         // Midpoint of low and high number
      char userAnswer = '-';  // User guess

      midNum = (highNum + lowNum) / 2;

      // Asks user for input
      System.out.print("Is it " + midNum + "? (l/h/y): ");
      userAnswer = scnr.next().charAt(0);

      if ((userAnswer != 'l') && (userAnswer != 'h')) { // Base case: found number
         System.out.println("Thank you!");
      }
      else {                                            // Recursive case: split into lower OR upper half
         if (userAnswer == 'l') {                       // Guess in lower half
            guessNumber(lowNum, midNum);                // Recursive call
         }
         else {                                         // Guess in upper half
            guessNumber(midNum + 1, highNum);           // Recursive call
         }
      }

      return;
   }

   public static void main(String[] args) {
      // Print game objective, user input commands
      System.out.println("Choose a number from 0 to 100.");
      System.out.println("Answer with:");
      System.out.println("   l (your num is lower)");
      System.out.println("   h (your num is higher)");
      System.out.println("   any other key (guess is right).");

      // Call recursive function to guess number
      guessNumber(0, 100);

      return;
   }
}