Question

通过这个程序，我想阅读并比较我在文本文件中给出的数字并打印出来只要数字连续三次上升，＆＃34;立即购买＆＃34; ＆＃34;只要数量连续三次下降，＆＃34; <＃em> 。

我的程序的问题是它只读取＆＃34; numbers.txt＆＃34;的15行中的13行。买卖是在错误的地方。

CONFIG.value = 1

文件numbers.txt：

26.375
  25.500
  25.125
  25.000
  25.250
  27.125
  28.250
  26.000
  25.500
  25.000
  25.125
  25.250
  26.375
  25.500
  25.500

预期产出：

1 26.375
  2 25.500
  3 25.125
  4 25.000
  5 25.250买
  6 27.125
  7 28.250
  8 26.000出售
  9 25.500
  10 25.000
  11 25.125买
  12 25.250
  13 26.375
  14 25.500出售
  15 25.500

Answer 1

您使用的a + 1 < array.length - 1可以转换为a < array.length - 2。我想你明白了＆amp;＆amp ;;中的第二个操作数。将迭代限制为13。

a < array.length && a < array.length - 2 = a < 15 && a < 13 = a < 13

我对您的代码进行了一些小的更改以使其正常工作;你可以重构它很多，但我坚持你的风格，所以你可以更好地理解逻辑。

    int num = 1;
    //print the 1st element
    System.out.println(num + "  " + array[0]);
    for (int a = 1; a < array.length; a++) {
        num++;
        System.out.print(num + "  " + (array[a]));
        //plz note that we check with the before, not after
        if (array[a] < array[a - 1]) {
            down++;
        } else if (array[a] > array[a - 1]) {
            up++;
        } else {
            same++;
        }
        //changed down > to down ==
        if ((up >= 3 && (down == 1 || same >= 1))) {
            System.out.print("  " + "sell");
            up = 0;
            same = 0;
        } 
        //changed up > to up ==
        else if ((down >= 3 && (up == 1 || same >= 1))) {
            System.out.print("  " + "buy");
            down = 0;
            same = 0;
        }
        System.out.println();
    }

回答OP评论：如果你想支持超过15条记录，你可以继续添加到列表中：

List<Double> list = new ArrayList<>();
while (scanner.hasNextDouble()) {
    list.add(scanner.nextDouble());
}
//if you want to work with array
Double[] array = new Double[list.size()];
array = list.toArray(array);

Answer 2

这是一个工作示例（必须将数组更改为列表）

int num = 0, up = 0, down = 0, same = 0;

FileInputStream file = new FileInputStream("numbers.txt");
Scanner scanner = new Scanner(file);
List<Double> list = new ArrayList<>();

while (scanner.hasNextDouble()) {
    list.add(scanner.nextDouble());
}

int position = 0;

while (position + 2 < list.size()) {
    Double[] nums = new Double[3];

    System.out.println(nums[0] = list.get(position));
    System.out.println(nums[1] = list.get(position + 1));
    System.out.println(nums[2] = list.get(position + 2));

    if (nums[1] > nums[0] && nums[2] > nums[1]) {
        System.out.println("buy");
        up++;
    } else if (nums[1] < nums[0] && nums[2] < nums[1]) {
        System.out.println("sell");
        down++;
    } else {
        same++;
    }
    position += 2;
}
System.out.println("Ups total: " + up);
System.out.println("Downs total: " + down);
System.out.println("Same total: " + same);

从txt文件中读取数字并进行比较

2 个答案: