Write your code in the file Compress.java. Your code should go into a method wit
ID: 3759653 • Letter: W
Question
Write your code in the file Compress.java. Your code should go into a method with the following signature. You may write your own main method to test your code. The graders will ignore your main method: You may NOT use any modules or classes from outside java.lang (do not add any "import" statements to your programs).
public static String compress (String original){}
Run-length encoding (RLE) is a simple "compression algorithm" (an algorithm which takes a block of data and reduces its size, producing a block that contains the same information in less space). It works by replacing repetitive sequences of identical data items with short "tokens" that represent entire sequences. Applying RLE to a string involves finding sequences in the string where the same character repeats. Each such sequence should be replaced by a "token" consisting of:
the number of characters in the sequence
the repeating character
If a character does not repeat, it should be left alone.
For example, consider the following string:
After applying the RLE algorithm, this string is converted into:
In the compressed string, "9w" represents a sequence of 9 consecutive lowercase "w" characters. "5e" represents 5 consecutive lowercase "e" characters, etc.
Write a method called compress that takes a string as input, compresses it using RLE, and returns the compressed string. Case matters - uppercase and lowercase characters should be considered distinct. You may assume that there are no digit characters in the input string. There are no other restrictions on the input - it may contain spaces or punctuation. There is no need to treat non-letter characters any differently from letters.
Explanation / Answer
public class Compress {
public static String compress(String original) {
StringBuilder str = new StringBuilder();
for (int i = 0; i < original.length(); i++) {
int count=0;
char ch = original.charAt(i);
for (int j = i; j < original.length(); j++) {
if (ch == original.charAt(j)) {
count++;
} else {
break;
}
}
if (count > 1) {
str.append(count);
}
str.append(original.charAt(i));
if (count > 1) {
i+=count;
}
}
return str.toString();
}
public static void main(String[] args) {
System.out.println(compress("qwwwwwwwwweeeeerrtyyyyyqqqqwEErTTT"));
}
}
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.