Jun 19, 2023
diff --git a/src/main/java/com/ctci/arraysandstrings/StringCompressionTest.java b/src/main/java/com/ctci/arraysandstrings/StringCompressionTest.java
 package com.ctci.arraysandstrings;

 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;

 import static org.junit.jupiter.api.Assertions.*;

 class StringCompressionTest {
    @Test
    void case1() {
        String input = "";
        String expectedOutput = "";
        String actualOutput = compressString(input);
        assertEquals(expectedOutput, actualOutput);
    }

    @Test
    void case2() {
        String input = "abc";
        String expectedOutput = "abc";
        String actualOutput = compressString(input);
        assertEquals(expectedOutput, actualOutput);
    }

    @Test
    void case3() {
        String input = "aaabbccc";
        String expectedOutput = "a3b2c3";
        String actualOutput = compressString(input);
        assertEquals(expectedOutput, actualOutput);
    }

    @Test
    void case4() {
        String input = "aaabbbccc";
        String expectedOutput = "a3b3c3";
        String actualOutput = compressString(input);
        assertEquals(expectedOutput, actualOutput);
    }

    @Test
    void case5() {
        String input = "abcd";
        String expectedOutput = "abcd";
        String actualOutput = compressString(input);
        assertEquals(expectedOutput, actualOutput);
    }


    private static String compressString(String str) {
        StringBuilder compressedSb = new StringBuilder();
        int countConsecutive = 0;
        for (int i = 0; i < str.length(); i++) {
            countConsecutive++;

            /* If next character is different than current, append this char to result. */
            if (i + 1 >= str.length() || str.charAt(i) != str.charAt(i + 1)) {
                compressedSb.append(str.charAt(i));
                compressedSb.append(countConsecutive);
                countConsecutive = 0;
            }
        }
        return compressedSb.length() < str.length() ? compressedSb.toString() : str;
    }
 }
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,66 @@
		package com.ctci.arraysandstrings;

		import org.junit.jupiter.api.AfterEach;
		import org.junit.jupiter.api.BeforeEach;
		import org.junit.jupiter.api.Test;

		import static org.junit.jupiter.api.Assertions.*;

		class StringCompressionTest {
		@Test
		void case1() {
		String input = "";
		String expectedOutput = "";
		String actualOutput = compressString(input);
		assertEquals(expectedOutput, actualOutput);
		}

		@Test
		void case2() {
		String input = "abc";
		String expectedOutput = "abc";
		String actualOutput = compressString(input);
		assertEquals(expectedOutput, actualOutput);
		}

		@Test
		void case3() {
		String input = "aaabbccc";
		String expectedOutput = "a3b2c3";
		String actualOutput = compressString(input);
		assertEquals(expectedOutput, actualOutput);
		}

		@Test
		void case4() {
		String input = "aaabbbccc";
		String expectedOutput = "a3b3c3";
		String actualOutput = compressString(input);
		assertEquals(expectedOutput, actualOutput);
		}

		@Test
		void case5() {
		String input = "abcd";
		String expectedOutput = "abcd";
		String actualOutput = compressString(input);
		assertEquals(expectedOutput, actualOutput);
		}


		private static String compressString(String str) {
		StringBuilder compressedSb = new StringBuilder();
		int countConsecutive = 0;
		for (int i = 0; i < str.length(); i++) {
		countConsecutive++;

		/* If next character is different than current, append this char to result. */
		if (i + 1 >= str.length() \|\| str.charAt(i) != str.charAt(i + 1)) {
		compressedSb.append(str.charAt(i));
		compressedSb.append(countConsecutive);
		countConsecutive = 0;
		}
		}
		return compressedSb.length() < str.length() ? compressedSb.toString() : str;
		}
		}