AN OVERVIEW OF COMPUTERS AND PROGRAMMING LANGUAGES - Java Programming: From Problem Analysis to Program Design - page 18

EXAMPLE 1-3
In this example, we design an algorithm to play a number-guessing game.
The objective is to randomly generate an integer greater than or equal to 0 and less than
100 . Then, prompt the player (user) to guess the number. If the player guesses the number
correctly, output an appropriate message. Otherwise, check whether the guessed
number is less than the random number. If the guessed number is less than the random
number generated, output the message, ''Your guess is lower than the number. Guess
again!''; otherwise, output the message, ''Your guess is higher than the number. Guess
again!''. Then, prompt the player to enter another number. The player is prompted to
guess the random number until the player enters the correct number.
The first step is to generate a random number, as described above. Java provides the
means to do so, which is discussed in Chapter 5. Suppose num stands for the random
number and guess stands for the number guessed by the player.
After the player enters the guess , you can compare the guess with the random number
as follows:
if (guess is equal to num)
Print "You guessed the correct number."
otherwise
if guess is less than num
Print "Your guess is lower than the number. Guess again!"
otherwise
Print "Your guess is higher than the number. Guess again!"
You can now design an algorithm as follows:
1. Generate a random number and call it num .
2. Repeat the following steps until the player has guessed the correct
number:
a. Prompt the player to enter guess .
b. if (guess is equal to num)
Print "You guessed the correct number."
otherwise
if guess is less than num
Print "Your guess is lower than the number. Guess again!"
otherwise
Print "Your guess is higher than the number. Guess again!"
In Chapter 5, we write a program that uses this algorithm to play the number-guessing
game.