java Javabat帮助：alarmClock

8 月，2 周 Questions & Answers 4772

我正在处理JavaBat问题，对自己的逻辑感到困惑

任务如下：

Given a day of the week encoded as 0=Sun, 1=Mon, 2=Tue, ...6=Sat, and a boolean indicating if we are on vacation, return a string of the form "7:00" indicating when the alarm clock should ring. Weekdays, the alarm should be "7:00" and on the weekend it should be "10:00". Unless we are on vacation -- then on weekdays it should be "10:00" and weekends it should be "off".

alarmClock(1, false) → "7:00" alarmClock(5, false) → "7:00" alarmClock(0, false) → "10:00"

这是我的密码：

            public String alarmClock(int day, boolean vacation) {
                if ( (day >=1 && day <=5) && (!vacation)) {
                    return "7:00";
                } else if ( (day >=1 && day <=5) && (vacation)) {
                    return "10:00";  
                } else {
                return "off";
                }  
            }

为什么这两项测试都失败了

报警时钟（0，假）→ “10:00”“关闭”X
报警时钟（6，假）→ “10:00”“关闭”X

当然，这条线涵盖了它

如果（天>；=1&；&；天<；=5）&&；（！假期））

共 (5) 个答案

# 1 楼答案

public String alarmClock(int day, boolean vacation) {

  if (((day==0)||(day==6))&&(!vacation)){
  return "10:00";
  }
  else if (((day!=0)||(day!=6))&&(!vacation)){
  return "7:00";
  }
  else if (((day==0)||(day==6))&&(vacation)){
  return "off";
  }
  else{
  return "10:00";
  }




}

# 2 楼答案
Surely, this line covers it?
```
if ((day >=1 && day <=5) && (!vacation)) 
```
不，那条线不包括它。如果日期是星期日或星期六（0或6），则“and”表达式的第一部分(day >=1 && day <=5)将为false，因为0和6不在1和5之间（包括1和5）

处理天0和6的唯一分支是您的else分支：“off”

这是一个很好的时机，可以使用helper方法来表达更接近英文描述的逻辑：
```
if ( isWeekday(day) ) {
    if ( vacation ) {
       //what to return here?
    } else {
       //what to return here?
    }
} else {
    if ( vacation ) {
       //what to return here?
    } else {
       //what to return here?
    }
}
```
然后您只需要实现isWeekday：
```
private boolean isWeekday(int day) {
   return /*fill this in*/;
}
```

# 3 楼答案

if ((day == 0 || day == 6) && (!vacation) || (day >= 1 && day <= 5) && (vacation)) {
        return "10:00";
    }
    if ((day >= 1 && day <= 5) && (!vacation)) {
        return "7:00";
    }

    return "off";

# 4 楼答案

虽然三元运算符在这里很有用，因为这个问题可以在一个返回语句中完成，但下面的代码允许可读性

public String alarmClock(int day, boolean vacation) {
      if(vacation){ //if we are on vacation
         if(day > 0 && day < 6){ //if it is weekday and we are on vacation
         return "10:00";
         }
         else return "off"; //it must be the weekend!
      } 
      //from here on out all the cases where vacation is true have been weeded out
      if(day > 0 && day < 6){
      return "7:00";
      }
      else return "10:00";
}

# 5 楼答案

这个怎么样

      public String alarmClock(int day, boolean vacation) {
            if (day >=1 && day <=5) {
                return vacation ? "10:00" : "7:00";
            } else {
                return vacation ? "off" : "10:00";
            }  
        }

注意，这取决于您的编码约定是否允许使用turnary运算符。但在这种情况下，我认为逻辑更容易理解

Python中文网

有 Java 编程相关的问题?