java - Push方法填充数组

Question

import java.util.*;

public class Lock {
    private int combination = 1729;
    private int input;
    int[] code = new int[4];

    public void push(int button){
        for(int i = 0; i < 4; i++){
            code[i] = button;
        }
    }
    public boolean open(){
        boolean results = false;
        int boop = 0;
        for (int i = 0;i < 4; i++){
            boop = boop*10 + code[i];
        }
        if(boop == combination){
            results = true;
        }
        return results;
    }
}
And here is the tester

public class LockTester
{
   public static void main(String[] args)
   {
      Lock myLock = new Lock();
      myLock.push(1);
      myLock.push(7);
      myLock.push(3);
      myLock.push(9);
      System.out.println(myLock.open());
      System.out.println("Expected: false");
      myLock.push(1);
      myLock.push(7);
      myLock.push(2);
      myLock.push(9);
      System.out.println(myLock.open());
      System.out.println("Expected: true");
      myLock.push(1);
      myLock.push(7);
      myLock.push(2);
      System.out.println(myLock.open());
      System.out.println("Expected: false");
      myLock.push(9);
      System.out.println(myLock.open());
      System.out.println("Expected: false");
      myLock.push(1);
      myLock.push(7);
      myLock.push(2);
      myLock.push(9);
      System.out.println(myLock.open());
      System.out.println("Expected: true");
   }
}

我每次都变得虚假。我不确定 Push 方法是否正确填充数组。

Answer 1

在当前的方法中，每次按下按钮时，您都会将所有 4 个按钮分配给同一输入。要解决此问题，您需要维护一些内部状态，表示哪些 key 按钮已被按入您的锁中。在我的方法中，用户可以按下 4 个组合按钮，然后尝试打开锁会将键盘重置为其原始状态:

public class Lock {
    private int combination = 1729;
    private static int CODE_LENGTH = 4;
    private int input = 0;       // this will keep track of which button to press
    int[] code = new int[CODE_LENGTH];

    public void push(int button){
        if (input >= CODE_LENGTH) {
            System.out.println("All keys have been entered.  Please try to open the lock.");
            return;
        }

        // assign a single button press here
        code[input] = button;
        ++input;
    }

    public boolean open() {
        input = 0;    // reset the keypad to its initial state here
        int boop = 0;
        for (int i=0; i < CODE_LENGTH; i++) {
            boop = boop*10 + code[i];
        }
        if (boop == combination) {
            return true;
        }

        return false;
    }
}