Java中用于时间戳而非索引的滑动窗口算法

我在考试中遇到了一个编码问题：在输入时，我有一个.csv文件，其中包含4列的交易数据行：

09:30:01.034,   36.99,  100,    V
09:30:11.034,   33.99,  205,    V
09:30:21.034,   36.99,  300,    V
09:30:21.334,   36.99,  76, V
09:30:21.534,   33.99,  100,    D
09:30:25.034,   36.99,  201,    V
09:30:28.034,   36.99,  202,    V
09:30:51.034,   36.99,  100,    D
09:31:01.554,   36.69,  120,    V
09:32:51.034,   36.99,  100,    D
09:33:01.034,   36.99,  99, V
09:33:05.734,   36.99,  100,    D

第一列值是其事务时间戳的第二部分（hh:mm:ss.mmm）；第四列表示事务的类型；第二个和第三个你可以忽略，我想；任务是开发一种算法，帮助我们分别找出在一分钟的某段时间（窗口）（非同一分钟）内发生的V交易的最大金额和D交易的最大金额

首先，我在谷歌上搜索了滑动窗口算法的问题，我发现了这个问题：（感谢Prerna Saini提供的Java版本的算法） 我当时试图实现滑动窗口技术，所以让我向您展示我的想法

公共类NormalMinuteWindow{
公共静态void main（字符串[]args）{
最终整数窗口=60000；
List tradeInfo=new ArrayList（）；
int-bestResultV=0，bestResultD=0，localResultV，localResultD；
NormalMinuteWindow应用程序=新的NormalMinuteWindow（）；
app.readFile（贸易信息）；
对于（int i=0；inext.getDate（）.getTime（））{
if（next.getExchange（）.equals（true））{
LocalResultTV++；
}否则{
localResultD++；
}
如果（计数器

然而，据说我的算法给出了错误的结果，因为在一分钟内出现了最大数量的“D”和“V”。我这里有两个问题：

• 我的算法实际上是滑动窗口算法吗
• 我在哪里犯了一个错误，产生了错误的结果，不管它是O（m*n）算法还是O（n）算法

---

不幸的是，我无法检查上述在线考试系统是否接受这一正确答案。考虑到和的评论，我想发布一个答案：

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;

public class NormalMinuteWindow {

    private static final int WINDOW = 60000;
    private static final String PATH_TO_CSV_FILE = "/path/to/file/windowAlg.csv";

    public static void main(String[] args) {
        NormalMinuteWindow app = new NormalMinuteWindow();
        List<TradeEntry> tradeInfo = Objects.requireNonNull(app.readFile(PATH_TO_CSV_FILE));
        Window window = new Window(tradeInfo.get(0).date.getTime(), WINDOW);

        //The sliding loop
//        for (int x = 1; x < 2; x++) {
            printAmountOfMatchesForCurrentWindow(tradeInfo, window); //show what's in the window
//            window.slide(tradeInfo.get(x).date.getTime()); //change the window's position over the list
//        }

    }

    private static final class Window {
        private long currentStartOfWindow;
        private long currentEndOfWindow;
        private long windowSize;

        Window(long currentStartOfWindow, long windowSize) {
            this.windowSize = windowSize;
            this.currentStartOfWindow = currentStartOfWindow;
            this.currentEndOfWindow = this.currentStartOfWindow + this.windowSize;
        }

        void slide(long newStartOfWindow) {
            this.currentStartOfWindow = newStartOfWindow;
            this.currentEndOfWindow = this.currentStartOfWindow + this.windowSize;
        }
    }

    private static final class TradeEntry {
        private final Timestamp date;
        private final Float price;
        private final Short size;
        private final Boolean exchange;

        public TradeEntry(Timestamp date, Float price, Short size, Boolean exchange) {
            this.date = date;
            this.price = price;
            this.size = size;
            this.exchange = exchange;
        }
    }

    private List<TradeEntry> readFile(String pathToFile) {
        List<TradeEntry> list = new ArrayList<>();

        String line = "";
        String cvsSplitBy = ",";

        try (BufferedReader br = new BufferedReader(new FileReader(pathToFile))) {
            while ((line = br.readLine()) != null) {
                String[] tradeInfo = line.split(cvsSplitBy);
                boolean exch = tradeInfo[3].trim().toUpperCase().equals("V");
                list.add(new TradeEntry(Timestamp.valueOf("2000-03-01 ".concat(tradeInfo[0])),
                        Float.parseFloat(tradeInfo[1]),
                        Short.parseShort(tradeInfo[2]),
                        exch));
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return list;
    }

    //performance optimization method
    private static int findIndexOfFirstElementInGivenWindow(List<TradeEntry> list, Window window) {
        for (int j = 0; j < list.size(); j++) {
            if (list.get(j).date.getTime() >= window.currentStartOfWindow) return j;
        }
        return 0;
    }

    //performance optimization method
    private static int findIndexOfLastElementInGivenWindow(List<TradeEntry> list, Window window) {
        for (int j = 0; j < list.size(); j++) {
            if (list.get(j).date.getTime() >= window.currentEndOfWindow) return j;
        }
        return 0;
    }

    private static void printAmountOfMatchesForCurrentWindow(List<TradeEntry> list, Window window) {

        int sumV = 0, sumD = 0;

        for (int i = findIndexOfFirstElementInGivenWindow(list, window); i <= findIndexOfLastElementInGivenWindow(list, window); i++) {

            TradeEntry next = list.get(i);

            if (window.currentStartOfWindow <= next.date.getTime() && window.currentEndOfWindow >= next.date.getTime()) {
                if (next.exchange) {
                    sumV++;
                } else {
                    sumD++;
                }
            }
        }

        System.out.println(sumV);
        System.out.println(sumD);
    }
}

导入java.io.BufferedReader；
导入java.io.FileReader；
导入java.io.IOException；
导入java.sql.Timestamp；
导入java.util.ArrayList；
导入java.util.List；
导入java.util.Objects；
公共类NormalMinuteWindow{
专用静态最终整数窗口=60000；
私有静态最终字符串路径到CSV文件=“/PATH/TO/FILE/windowAlg.CSV”；
公共静态void main（字符串[]args）{
NormalMinuteWindow应用程序=新的NormalMinuteWindow（）；
List tradeInfo=Objects.requirennull（app.readFile（路径到CSV文件））；
窗口=新窗口（tradeInfo.get（0.date.getTime（），窗口）；
//滑动环
//对于（int x=1；x<2；x++）{
printAmountOfMatchesForCurrentWindow（tradeInfo，window）；//显示窗口中的内容
//slide（tradeInfo.get（x.date.getTime（））；//更改窗口在列表中的位置
//        }
}
私有静态最终类窗口{
私人长时间窗口；
私人长假；
私有长窗口大小；
窗口（长当前开始窗口，长窗口大小）{
this.windowSize=windowSize；
this.currentStartOfWindow=currentStartOfWindow；
this.currentEndOfWindow=this.currentStartOffWindow+this.WindowsSize；
}
空白幻灯片（长新闻起始窗口）{
this.currentStartOfWindow=newstartOfWindows；
this.currentEndOfWindow=this.currentStartOffWindow+this.WindowsSize；
}
}
私有静态最终类TradeEntry{
私人最终时间戳日期；
私人最终浮动价格；
私人最终短尺寸；
私有最终布尔交换；
公共交易条目（时间戳日期、浮动价格、短码、布尔交换）{
this.date=日期；
这个价格=价格；
这个。大小=大小；
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;

public class NormalMinuteWindow {

    private static final int WINDOW = 60000;
    private static final String PATH_TO_CSV_FILE = "/path/to/file/windowAlg.csv";

    public static void main(String[] args) {
        NormalMinuteWindow app = new NormalMinuteWindow();
        List<TradeEntry> tradeInfo = Objects.requireNonNull(app.readFile(PATH_TO_CSV_FILE));
        Window window = new Window(tradeInfo.get(0).date.getTime(), WINDOW);

        //The sliding loop
//        for (int x = 1; x < 2; x++) {
            printAmountOfMatchesForCurrentWindow(tradeInfo, window); //show what's in the window
//            window.slide(tradeInfo.get(x).date.getTime()); //change the window's position over the list
//        }

    }

    private static final class Window {
        private long currentStartOfWindow;
        private long currentEndOfWindow;
        private long windowSize;

        Window(long currentStartOfWindow, long windowSize) {
            this.windowSize = windowSize;
            this.currentStartOfWindow = currentStartOfWindow;
            this.currentEndOfWindow = this.currentStartOfWindow + this.windowSize;
        }

        void slide(long newStartOfWindow) {
            this.currentStartOfWindow = newStartOfWindow;
            this.currentEndOfWindow = this.currentStartOfWindow + this.windowSize;
        }
    }

    private static final class TradeEntry {
        private final Timestamp date;
        private final Float price;
        private final Short size;
        private final Boolean exchange;

        public TradeEntry(Timestamp date, Float price, Short size, Boolean exchange) {
            this.date = date;
            this.price = price;
            this.size = size;
            this.exchange = exchange;
        }
    }

    private List<TradeEntry> readFile(String pathToFile) {
        List<TradeEntry> list = new ArrayList<>();

        String line = "";
        String cvsSplitBy = ",";

        try (BufferedReader br = new BufferedReader(new FileReader(pathToFile))) {
            while ((line = br.readLine()) != null) {
                String[] tradeInfo = line.split(cvsSplitBy);
                boolean exch = tradeInfo[3].trim().toUpperCase().equals("V");
                list.add(new TradeEntry(Timestamp.valueOf("2000-03-01 ".concat(tradeInfo[0])),
                        Float.parseFloat(tradeInfo[1]),
                        Short.parseShort(tradeInfo[2]),
                        exch));
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return list;
    }

    //performance optimization method
    private static int findIndexOfFirstElementInGivenWindow(List<TradeEntry> list, Window window) {
        for (int j = 0; j < list.size(); j++) {
            if (list.get(j).date.getTime() >= window.currentStartOfWindow) return j;
        }
        return 0;
    }

    //performance optimization method
    private static int findIndexOfLastElementInGivenWindow(List<TradeEntry> list, Window window) {
        for (int j = 0; j < list.size(); j++) {
            if (list.get(j).date.getTime() >= window.currentEndOfWindow) return j;
        }
        return 0;
    }

    private static void printAmountOfMatchesForCurrentWindow(List<TradeEntry> list, Window window) {

        int sumV = 0, sumD = 0;

        for (int i = findIndexOfFirstElementInGivenWindow(list, window); i <= findIndexOfLastElementInGivenWindow(list, window); i++) {

            TradeEntry next = list.get(i);

            if (window.currentStartOfWindow <= next.date.getTime() && window.currentEndOfWindow >= next.date.getTime()) {
                if (next.exchange) {
                    sumV++;
                } else {
                    sumD++;
                }
            }
        }

        System.out.println(sumV);
        System.out.println(sumD);
    }
}