如何调用此Java代码中的方法和修复错误？

Question

我是一个Java新手，我试图让这段代码运行，但似乎总是给我带来错误。我也试过使用sum和其他函数。我做错了什么？

这里是我正在练习的问题-

求线的总长度之和。一条线被定义为数字线上的两个点A和B。例如，如果A= -3，B= 10，线的长度是13。这是因为数字线上的-3到10之间的距离是13个单位(10 -(-3) = 13)。同样地，如果A=9，B=5时，线的长度应该是4个单位，而数字线上的距离是4个单位(9-5= 4)。

输入-将有2行，每一行将有数字A&B整数分隔的空间。

输出-这应该返回由用户输入的2行的长度之和。

样本输入：

5 9
-10 3

预期产出：

17

说明:第一行代表第一行坐标，即A= 5，B= 9。第二线代表第二线坐标，即A= -10，B= 3。

第一行的长度= 4，第二线的长度是13，因此输出为17。

我的代码-

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class Source{


    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        String[] firstLineCoordinates = br.readLine().split(" ");
        int a1 = Integer.parseInt(firstLineCoordinates[0]);
        int b1 = Integer.parseInt(firstLineCoordinates[1]);

String[] secondLineCoordinates = br.readLine().split(" ");
        int a2 = Integer.parseInt(secondLineCoordinates[0]);
        int b2 = Integer.parseInt(secondLineCoordinates[1]);

        Line firstLine = new Line(a1, b1);
        Line secondLine = new Line(a2, b2);

        int totalSumOfLines = getTotalSumOfLines(firstLine, secondLine);
        System.out.println(totalSumOfLines);

        br.close();
    }

    private static int getTotalSumOfLines(Line firstLine, Line secondLine) {
        int sum = totalSumOfLines;
        return sum((b2 - a2) + (b1 - a1));
         // ERROR IN THIS METHOD
         
    }

    public static class Line {
        private int a;
        private int b;
public Line(int a, int b) {
            this.a = a;
            this.b = b;
        }

        public int getA() {
            return a;
        }

        public int getB() {
            return b;
        }
    }
}

编译时间错误-

Source.java:29: error: cannot find symbol
        int sum = totalSumOfLines;
                  ^
  symbol:   variable totalSumOfLines
  location: class Source
Source.java:30: error: cannot find symbol
        return sum((b2 - a2) + (b1 - a1));
                    ^
  symbol:   variable b2
  location: class Source
Source.java:30: error: cannot find symbol
        return sum((b2 - a2) + (b1 - a1));
                         ^
  symbol:   variable a2
  location: class Source
Source.java:30: error: cannot find symbol
        return sum((b2 - a2) + (b1 - a1));
                                ^
  symbol:   variable b1
  location: class Source
Source.java:30: error: cannot find symbol
        return sum((b2 - a2) + (b1 - a1));
                                 ^
symbol:   variable a1
  location: class Source
5 errors

Answer 1

尝尝这个

private static int getTotalSumOfLines(Line firstLine, Line secondLine) {
    int sum = 0;
    if(firstLine.getA() > firstLine.getB())
        sum = sum + (firstLine.getA() - firstLine.getB());
    else
        sum = sum + (firstLine.getB() - firstLine.getA());
    if(SecondLine.getA() > secondLine.getB())
        sum = sum + (SecondLine.getA() - secondLine.getB());
    else
        sum = sum + (secondLine.getB() - SecondLine.getA());
    return sum;
         
}

Answer 2

私有静态int getTotalSumOfLines(Line firstLine，Line secondLine) {

     // take this to getTotalSumOfLines

    int sum1= Math.abs((firstLine.getA() - firstLine.getB()));
    int sum2= Math.abs((secondLine.getA() - secondLine.getB()));
    return sum1+sum2;

}