运行代码时我将如何实现-1

Question

代码工作正常，但我似乎无法使用-1作为我用来计算平均值的唯一输入来运行代码。

import java.util.*;

class Bowling {

    public static void main(String args[]) {
        Scanner keyboard = new Scanner(System.in);
        int G = 0;

        int scores = 0;
        double avg = 0;
        double highest_average = 0;
        int times = 0;
        int players = 4;

        for (int i = 1; i <= players; i++) {
            System.out.println("Player " + i);
            if (avg > highest_average)
                highest_average = avg;
            do {
                System.out.println("Enter your bowling score:");
                G = keyboard.nextInt();
                scores += G;
                times++;
            }
            while ((G != -1));
            scores += +1;
            times = times - 1;
            avg = (scores) / (times);
            System.out.printf("Average= %.2f\n", avg);
            scores = 0;
            times = 0;
            System.out.println("");
        }

        System.out.println("Highest average:" + highest_average);
    }
}

这是一个示例运行：因此，代码工作正常，但是我不知道是否应该使用IF语句让-1计算为平均值。

Player 1

Enter your bowling score:

300

Enter your bowling score:

222

Enter your bowling score:

-1

Average= 261.00

Player 2

Enter your bowling score:

210

Enter your bowling score:

211

Enter your bowling score:

300

Enter your bowling score:

-1

Average= 240.00

Player 3

Enter your bowling score:

233

Enter your bowling score:

-1

Average= 233.00

Player 4

Enter your bowling score:

112

Enter your bowling score:

-1

Average= 112.00

Highest average:261.00

这是另一次运行，但首先输入-1

Player 1

Enter your bowling score:

-1 

Exception in thread "main" java.lang.ArithmeticException: / by zero
at LabQuiz1.main(LabQuiz1.java:33)    // I keep getting this when -1 is inputted I have been thinking of using a IF statement to tell the code that if  -1 is implemented it should still calculate 0 as the average. 

Answer 1

您的代码在这里：

scores += + 1;//change to scores+=1
times = times - 1; //in do while loop you increment by one and now you decrement it and hence 0
avg = (scores)/(times);//you could check for times if 0 here. and you are dividing by integer if you want accurate decimal result change denominator to decimal as well.

更改为：

scores += 1;
times = times - 1; 
avg = times == 0? 0: (scores/(times * 1.));

Answer 2

如果使用-1作为特殊数字退出处理，则应使用if条件不将输入作为计算的一部分进行处理。

double highest_average=0;
int players = 4;

for(int i =1; i<=players; i++) {
  double avg = 0;
  int times = 0;
  int scores = 0;

  System.out.println("Player " + i);
  if (avg > highest_average) 
    highest_average= avg; 

  do
  {
    System.out.println("Enter your bowling score:");
    G = keyboard.nextInt();
    if(G ==-1)
      break;

    scores += G;
    times++;
  }
  while(true);   

  // remove the following lines that aren't necessary anymore
  //scores += + 1;
  //times = times - 1; 

  if(times > 0)
    avg = (scores)/(times);

  System.out.printf("Average= %.2f\n", avg);
  //scores =0; times =0; 
  System.out.println("");
}

如果您不想允许负数， 请相应地更改if条件。

您可以将do / while条件修改为do ... while（true），因为现在退出break语句上的循环。

您可以将avg ， scores和times变量移动到for循环内，因为它们仅在for循环的范围内使用。 这些变量将初始化为0，而不需要在底部再次初始化值。