java - 游程编码程序问题

Question

我是 Java 和一般编程的新手...我在实现游程编码程序时遇到问题，其中的字符串来自用户输入。 (例如: KKKKKKKKKKKKKBCCDDDDDDDDDDDDDDDKKKKKMNUUUGGGGG) 将根据他们输入的标志字符进行编码。因此该特定字符串将如下所示: $K13BCC$D15$K5MNUUU$G5

有人可以帮我找出问题所在吗？我不断得到这个作为我的输出:$K13BCC$D14$K4MNUUU

我的程序似乎跳过了最后一个字母，并且其中一些字母少了一个。任何帮助将不胜感激!

我为我的困惑代码道歉。我知道这不是那么好。只是想找出这里出了什么问题......

import java.util.Scanner;

public class RunLengthEncoding {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        System.out.print("Enter input string: ");
        String inputString = input.next();

        System.out.print("Enter flag character: ");
        String flagCharacter = input.next();

        Boolean validInput = false;

        for (int i = 0; i < inputString.length(); i++) {
            if (Character.isUpperCase(inputString.charAt(i))) {
                validInput = true;

            } else {
                System.out.print("Bad input.");
            }

        }

        char repeatedLetter = inputString.charAt(0);

        if (validInput) { // if the input is valid, continue
            int counter = 0; // set counter equal to 0
            for (int i = 0; i < inputString.length(); i++) { // iterate through the input string

                if (repeatedLetter == (inputString.charAt(i))) { // if the current letter is equal to the next
                    counter++; // increment the counter
                    repeatedLetter = inputString.charAt(i); // set the repeated letter to the next letter
                } else { // if the current letter is not equal to the next letter
                    if (counter > 3) { // and if the counter is greater than 3
                        System.out.print(flagCharacter + repeatedLetter + counter); // print the encoded string
                    } else { // if the counter is not greater than 3
                        for (int j = counter; j >= 0; j--) { // for every number in counter
                            System.out.print(repeatedLetter); // print the current repeated letter for as many times as it appears
                        }

                    }
                    repeatedLetter = inputString.charAt(i); // set the new repeated letter
                    counter = 0; // reset counter to 0

                }
            }

        }

    }

}

Answer 1

首先，您应该设置 counter外部变量为 1 else阻止，因为您正在设置 repeatedValue就在它之前，这算作该字母的一次计数。您还需要考虑字符串中的最后一个字符序列，因此您需要最后一个 if当你到达末尾时，在循环之外声明:

int counter = 0; // set counter equal to 0
for (int i = 0; i < inputString.length(); i++) { // iterate through the input string

    if (repeatedLetter == (inputString.charAt(i))) { // if the current letter is equal to the next
        counter++; // increment the counter
    } else { // if the current letter is not equal to the next letter
        if (counter > 3) { // and if the counter is greater than 3
            System.out.print(flagCharacter + repeatedLetter + counter); // print the encoded string
        } else { // if the counter is not greater than 3
            for (int j = counter; j > 0; j--) { // for every number in counter
                System.out.print(repeatedLetter); // print the current repeated letter for as many times as it appears
            }

        }
        repeatedLetter = inputString.charAt(i); // set the new repeated letter
        counter = 1; // reset counter to 1
    }
}

// We at the end of the string now, print everything else
if (counter > 3) { // and if the counter is greater than 3
    System.out.print(flagCharacter + repeatedLetter + counter); // print the encoded string
} else { // if the counter is not greater than 3
    for (int j = counter; j > 0; j--) { // for every number in counter
        System.out.print(repeatedLetter); // print the current repeated letter for as many times as it appears
    }

}