java - 如何将用户输入保存在数组中并稍后检查它是否已经在java中的数组中？

Question

我必须做一个随机猜数字游戏，每轮我的猜测次数限制为 10 次。我感到困惑的部分是我需要检查该轮中是否重复了任何猜测。我知道我必须创建一个数组并将数字存储在其中，但我不知道该怎么做。

这是我的整个代码，其他一切都按预期工作:

import java.util.Scanner;
import java.util.Random;
public class GuessingGame {

 private static final int MIN_NUMBER = 1;
 private static final int MAX_NUMBER = 205;
 private static final int QUIT_VALUE = -1;
 private static final int LOSE_VALUE = -2;
 private static final int MAX_GAMES = 2;
 private static final int MAX_GUESSES = 10;
 private static final int HINT_THRESHOLD = 5;
 private static final int BACKDOOR_VALUE = -314;

 private static final String NOPE_MSG = "nope...";
 private static final String NOPE_NOPE_MSG =
  "you've already guessed that wrong guess...";
 private static final String INVALID_INPUT_BEGIN =
  "*** invalid input -- ";
 private static final String INVALID_INPUT_LESS_MIN_MSG =
  INVALID_INPUT_BEGIN + "must be greater than " + (MIN_NUMBER - 1);
 private static final String INVALID_INPUT_GREATER_MAX_MSG =
  INVALID_INPUT_BEGIN + "must be less than " + (MAX_NUMBER + 1);
 private static final String INVALID_INPUT_YN_MSG =
  INVALID_INPUT_BEGIN + "must be n or y";
 private static final String WINNER_MSG =
  "you're a winner... # of guesses: ";
 private static final String LOSER_MSG =
  "too many guesses entered... the number was ";
 private static final String QUITTER_MSG =
  "you're a quitter... the number was ";
 private static final String MAX_GAMES_PLAYED_MSG =
  "you've played the maximum number (" + MAX_GAMES + ") of games";
 private static final String ENTER_GUESS_PROMPT =
  "enter a guess between " + MIN_NUMBER + " and " + MAX_NUMBER +
  " (" + QUIT_VALUE + " to quit): ";
 private static final String PLAY_AGAIN_PROMPT =
  "Do you want to play again (n or y)? ";

 private static final String BOLD_BEGIN = "*** ";
 private static final String BOLD_END = " ***";
 private static final String PLAY_MSG = " playing the CSC" + MAX_NUMBER +
  " guessing game." + BOLD_END;
 private static final String WELCOME_MSG =
  BOLD_BEGIN + "Hello! Have fun" + PLAY_MSG;
 private static final String THANKS_MSG =
  BOLD_BEGIN + "Thanks for" + PLAY_MSG;

 static Random rng = new Random(System.currentTimeMillis());
 static Scanner stdin = new Scanner(System.in);
 static Scanner scan = new Scanner(System.in);

 static int guess;
 static int numberOfGames = 0;
 static int numberOfWins = 0;
 static int numberOfLoses = 0;
 static boolean endStart = true; // Check if this boolean is used

 public static void main(String[] args) {

  PlayGame();
  PostGame();
  EndGame();
 }

 public static void PlayGame() {

  int guessCounter = 0;
  int n = MIN_NUMBER + rng.nextInt(MAX_NUMBER);

  System.out.println(WELCOME_MSG);
  boolean test = true;
  do {

   System.out.println();
   System.out.print(ENTER_GUESS_PROMPT);
   guess = stdin.nextInt();
   guessCounter = guessCounter + 1;

   if (guess < MIN_NUMBER && guess != BACKDOOR_VALUE &&
    guess != QUIT_VALUE) {
    System.out.println(INVALID_INPUT_LESS_MIN_MSG + "\n");
   }

   if (guess > MAX_NUMBER) {
    System.out.println(INVALID_INPUT_GREATER_MAX_MSG + "\n");
   }

   // Giving the user the answer 
   if (guess == BACKDOOR_VALUE) {
    System.out.println(n);
   }

   // Quiting the round and giving the chance to end the game
   if (guess == QUIT_VALUE) {
    System.out.println((QUITTER_MSG + n) + "\n" +
     PLAY_AGAIN_PROMPT);
    numberOfLoses++;
    String val = scan.next();
    if (val.equalsIgnoreCase("y")) {
     numberOfGames++;
     PlayGame();
    }

    if (val.equalsIgnoreCase("n")) {
     System.out.println(THANKS_MSG);
     test = false;
     PostGame();
     break;
    }


   }

   // Correct guess on the last try
   if (guessCounter == MAX_GUESSES || guess == n) {
    numberOfGames++;
    System.out.println(WINNER_MSG + guessCounter);
    numberOfWins++;
    System.out.println(PLAY_AGAIN_PROMPT);
    String val = scan.next();
    if (val.equalsIgnoreCase("y"))
     PlayGame();
    if (val.equalsIgnoreCase("n")) {
     System.out.println(THANKS_MSG);
     test = false;
     PostGame();
     break;
    }
   }

   // Max games
   if (numberOfGames == MAX_GAMES) {
    System.out.println(MAX_GAMES_PLAYED_MSG);
    test = false;
    PostGame();
    break;
   }

   // Max guesses
   if (guessCounter == MAX_GUESSES) {
    numberOfGames++;
    System.out.println(LOSER_MSG + n + "\n" + PLAY_AGAIN_PROMPT);
    numberOfLoses++;
    String val = scan.next();
    if (val.equalsIgnoreCase("y"))
     PlayGame();
    if (val.equalsIgnoreCase("n")) {
     System.out.println(THANKS_MSG);
     test = false;
     PostGame();
     break;
    }
   }

   // Guessing in the range of the bonds
   if (guess > MIN_NUMBER || guess < MAX_NUMBER) {
    if (guess != n) {
     System.out.print(NOPE_MSG);
    }
    if (guess == n) {
     numberOfGames++;
     System.out.println(WINNER_MSG + guessCounter);
     numberOfWins++;
     System.out.println(PLAY_AGAIN_PROMPT);
     String val = scan.next();
     if (val.equalsIgnoreCase("y"))
      PlayGame();
     if (val.equalsIgnoreCase("n")) {
      System.out.println(THANKS_MSG);
      test = false;
      PostGame();
      break;
     }
    }
   }

   // Giving hints after 5 tries until the max # of guesses
   if (guessCounter == HINT_THRESHOLD ||
    guessCounter == (HINT_THRESHOLD + 1) ||
    guessCounter == (HINT_THRESHOLD + 2) ||
    guessCounter == (HINT_THRESHOLD + 3) ||
    guessCounter == (HINT_THRESHOLD + 4) ||
    guessCounter == (HINT_THRESHOLD + 5)) {
    if (guess != n && guess > n) {
     System.out.println(" lower");
    }
    if (guess != n && guess < n) {
     System.out.println(" higher");
    }
   }
  }
  while (guess > MIN_NUMBER || guess < MAX_NUMBER);
 }

 // Post game information
 public static void PostGame() {
  int winningPct = 0;
  System.out.print("Played: " + numberOfGames + ";" +
   " Won: " + numberOfWins + ";" +
   " Lost: " + numberOfLoses + ";");
  if (numberOfGames != 0) {
   System.out.println(" winningPct: " +
    (winningPct = numberOfWins / numberOfGames));
  } else {
   winningPct = 0;
  }
  EndGame();
 }

 // Ending the game
 public static void EndGame() {

 }
}

Answer 1

使用数组来检查是否提前猜到了一个数字并不是最佳方法。即使尝试次数不是很高，它也会限制您可以猜测的数字范围。此外，数组的大多数索引通常将保持为空。

所以，最好你可以使用Set<Integer> (或 Set<Long> 取决于猜测的数字的允许范围)。下面是一个示例代码:

Set<Integer> guessedNumbers = new HashSet<Integer>();
if(guessedNumbers.contains(guess)){
    System.out.println("You already guessed this earlier");
}
else{
    guessedNumbers.add(guess);
}