Question

我需要这段代码来压缩和解压缩用户给出的字符串，压缩用户将输入“java compression -c”或“java compression”。要解压缩，它将是“java compression -d”。任何帮助，将不胜感激。它现在将编译并运行;但是，当您输入字符串时，它只会打印出压缩而不是压缩字符串。

import java.util.*;
public class practice
{
    public static void main(String args[])
    {
        Scanner scan = new Scanner(System.in);
        String originalString = scan.nextLine();
        String compressedString = "";
        int index = 0;
        int numReps = 0;
        char nextChar = ' ';
        if (args.length==0 || args[0].equals("-c"))
        {
            System.out.println("compress");
            String s = scan.next();
            compress(originalString);
            System.out.println(compressedString);
        }
        else if (args[0].equals("-d"))
        {
            System.out.println("decompress");
            decompress(compressedString);
        }
        else
        {
            System.out.println("Error! Unknown mode.");
        }

    }

    public static void compress(String originalString)
    {
        int index = 0;
        int numReps = 0;
        char nextChar = ' ';
        while (index < originalString.length())
        {
            numReps = 0;
            char c = originalString.charAt(index);
            if (!Character.isDigit(c))
            {
                nextChar = c;
                index++;
            }
            else
            {
                while (Character.isDigit(c))
                {
                    int temp = Integer.parseInt(""+c);
                    numReps = temp;
                    index++;
                    if (index >= originalString.length()) break;
                    c = originalString.charAt(index);
                }
                for (int i =0; i<numReps; i++)
                {
                    System.out.println(nextChar);
                }
            }
        }
    }

    public static void decompress(String compressedString)
    {
        int index = 0;
        int numReps = 0;
        char nextChar = ' ';

        while (index < compressedString.length())
        {
            numReps = 0;
            char c = compressedString.charAt(index);
            if (!Character.isDigit(c))
            {
                nextChar = c;
                index++;
            }
            else
            {
                while (Character.isDigit(c))
                {
                    int temp = Integer.parseInt(""+c);
                    numReps = (numReps*10) + temp;
                    index++;
                    if (index >= compressedString.length()) break;
                    c = compressedString.charAt(index);
                }
                for (int i =0; i<numReps; i++)
                {
                    System.out.println(nextChar);
                }
            }   
        }
    }
}

Answer 1

您忘记了方法定义的类型参数：

public static void decompress(compressedString)

应该是

public static void decompress(String compressedString)

甚至更好

public static void decompress(final String compressedString)

Answer 2

您的代码中出现了两个问题（据我所知）： -

public static void decompress(compressedString)实际应该是public static void decompress(**String** compressedString)。您必须告诉method它将收到的argument类型为String。
使用compress和decompress方法while (index < input.length());。最后检查; 。你真的想要吗？您永远不会执行while循环，因为您在它开始之前就已经终止了它。

在Java中压缩和解压缩字符串的程序

2 个答案: