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refactor: StringCompression (#5410)

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refactor: StringCompression

Co-authored-by: alxkm <alx@alx.com>
This commit is contained in:
Alex Klymenko 2024-08-27 12:02:50 +02:00 committed by GitHub
parent af7c425010
commit e3ad3761fd
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2 changed files with 9 additions and 11 deletions
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17
src/main/java/com/thealgorithms/strings/StringCompression.java
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@ -1,7 +1,8 @@
package com.thealgorithms.strings; package com.thealgorithms.strings;
/* References : https://en.wikipedia.org/wiki/Run-length_encoding
* String compression algorithm deals with encoding the string, that is, shortening the size of the /**
* string * References : https://en.wikipedia.org/wiki/Run-length_encoding
* String compression algorithm deals with encoding the string, that is, shortening the size of the string
* @author Swarga-codes (https://github.com/Swarga-codes) * @author Swarga-codes (https://github.com/Swarga-codes)
*/ */
public final class StringCompression { public final class StringCompression {
@ -14,19 +15,16 @@ public final class StringCompression {
* @return the compressed character array as string * @return the compressed character array as string
*/ */
public static String compress(String input) { public static String compress(String input) {
// Keeping the count as 1 since every element present will have atleast a count // Keeping the count as 1 since every element present will have at least a count of 1
// of 1
int count = 1; int count = 1;
String compressedString = ""; String compressedString = "";
// Base condition to check whether the array is of size 1, if it is then we // Base condition to check whether the array is of size 1, if it is then we return the array
// return the array
if (input.length() == 1) { if (input.length() == 1) {
return "" + input.charAt(0); return "" + input.charAt(0);
} }
// If the array has a length greater than 1 we move into this loop // If the array has a length greater than 1 we move into this loop
for (int i = 0; i < input.length() - 1; i++) { for (int i = 0; i < input.length() - 1; i++) {
// here we check for similarity of the adjacent elements and change the count // here we check for similarity of the adjacent elements and change the count accordingly
// accordingly
if (input.charAt(i) == input.charAt(i + 1)) { if (input.charAt(i) == input.charAt(i + 1)) {
count = count + 1; count = count + 1;
} }
@ -54,7 +52,6 @@ public final class StringCompression {
public static String appendCount(String res, int count, char ch) { public static String appendCount(String res, int count, char ch) {
if (count > 1) { if (count > 1) {
res += ch + "" + count; res += ch + "" + count;
count = 1;
} else { } else {
res += ch + ""; res += ch + "";
} }

3
src/test/java/com/thealgorithms/strings/StringCompressionTest.java
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@ -1,4 +1,5 @@
package com.thealgorithms.strings; package com.thealgorithms.strings;
import static org.junit.jupiter.api.Assertions.assertEquals; import static org.junit.jupiter.api.Assertions.assertEquals;
import org.junit.jupiter.params.ParameterizedTest; import org.junit.jupiter.params.ParameterizedTest;
@ -6,7 +7,7 @@ import org.junit.jupiter.params.provider.CsvSource;
public class StringCompressionTest { public class StringCompressionTest {
@ParameterizedTest @ParameterizedTest
@CsvSource({"a,a", "aabbb,a2b3", "abbbc,ab3c", "aabccd,a2bc2d"}) @CsvSource({"'a', 'a'", "'aabbb', 'a2b3'", "'abbbc', 'ab3c'", "'aabccd', 'a2bc2d'", "'aaaabbbcccc', 'a4b3c4'", "'abcd', 'abcd'", "'aabbccdd', 'a2b2c2d2'", "'aaabbaa', 'a3b2a2'", "'', ''", "'a', 'a'", "'aaaaa', 'a5'", "'aabb', 'a2b2'", "'aabbbaaa', 'a2b3a3'", "'qwerty', 'qwerty'"})
void stringCompressionTest(String input, String expectedOutput) { void stringCompressionTest(String input, String expectedOutput) {
String output = StringCompression.compress(input); String output = StringCompression.compress(input);
assertEquals(expectedOutput, output); assertEquals(expectedOutput, output);