diff --git a/DIRECTORY.md b/DIRECTORY.md
index 833062d17d42..ac2e921e6081 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -686,6 +686,7 @@
* [Isomorphic](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/Isomorphic.java)
* [KMP](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/KMP.java)
* [LetterCombinationsOfPhoneNumber](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/LetterCombinationsOfPhoneNumber.java)
+ * [LongestCommonPrefix](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/LongestCommonPrefix.java)
* [LongestNonRepetitiveSubstring](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/LongestNonRepetitiveSubstring.java)
* [LongestPalindromicSubstring](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/LongestPalindromicSubstring.java)
* [Lower](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/Lower.java)
@@ -1311,6 +1312,7 @@
* [HorspoolSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/HorspoolSearchTest.java)
* [IsomorphicTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/IsomorphicTest.java)
* [LetterCombinationsOfPhoneNumberTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/LetterCombinationsOfPhoneNumberTest.java)
+ * [LongestCommonPrefixTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/LongestCommonPrefixTest.java)
* [LongestNonRepetitiveSubstringTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/LongestNonRepetitiveSubstringTest.java)
* [LongestPalindromicSubstringTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/LongestPalindromicSubstringTest.java)
* [LowerTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/LowerTest.java)
diff --git a/src/main/java/com/thealgorithms/strings/LongestCommonPrefix.java b/src/main/java/com/thealgorithms/strings/LongestCommonPrefix.java
new file mode 100644
index 000000000000..0fabdaa2658b
--- /dev/null
+++ b/src/main/java/com/thealgorithms/strings/LongestCommonPrefix.java
@@ -0,0 +1,22 @@
+package com.thealgorithms.strings;
+
+import java.util.Arrays;
+
+public final class LongestCommonPrefix {
+ public String longestCommonPrefix(String[] strs) {
+ if (strs == null || strs.length == 0) {
+ return "";
+ }
+
+ Arrays.sort(strs);
+ String shortest = strs[0];
+ String longest = strs[strs.length - 1];
+
+ int index = 0;
+ while (index < shortest.length() && index < longest.length() && shortest.charAt(index) == longest.charAt(index)) {
+ index++;
+ }
+
+ return shortest.substring(0, index);
+ }
+}
diff --git a/src/test/java/com/thealgorithms/strings/LongestCommonPrefixTest.java b/src/test/java/com/thealgorithms/strings/LongestCommonPrefixTest.java
new file mode 100644
index 000000000000..580a2726d285
--- /dev/null
+++ b/src/test/java/com/thealgorithms/strings/LongestCommonPrefixTest.java
@@ -0,0 +1,73 @@
+package com.thealgorithms.strings;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class LongestCommonPrefixTest {
+
+ private final LongestCommonPrefix longestCommonPrefix = new LongestCommonPrefix();
+
+ @Test
+ public void testCommonPrefix() {
+ String[] input = {"flower", "flow", "flight"};
+ String expected = "fl";
+ assertEquals(expected, longestCommonPrefix.longestCommonPrefix(input));
+ }
+
+ @Test
+ public void testNoCommonPrefix() {
+ String[] input = {"dog", "racecar", "car"};
+ String expected = "";
+ assertEquals(expected, longestCommonPrefix.longestCommonPrefix(input));
+ }
+
+ @Test
+ public void testEmptyArray() {
+ String[] input = {};
+ String expected = "";
+ assertEquals(expected, longestCommonPrefix.longestCommonPrefix(input));
+ }
+
+ @Test
+ public void testNullArray() {
+ String[] input = null;
+ String expected = "";
+ assertEquals(expected, longestCommonPrefix.longestCommonPrefix(input));
+ }
+
+ @Test
+ public void testSingleString() {
+ String[] input = {"single"};
+ String expected = "single";
+ assertEquals(expected, longestCommonPrefix.longestCommonPrefix(input));
+ }
+
+ @Test
+ public void testCommonPrefixWithDifferentLengths() {
+ String[] input = {"ab", "a"};
+ String expected = "a";
+ assertEquals(expected, longestCommonPrefix.longestCommonPrefix(input));
+ }
+
+ @Test
+ public void testAllSameStrings() {
+ String[] input = {"test", "test", "test"};
+ String expected = "test";
+ assertEquals(expected, longestCommonPrefix.longestCommonPrefix(input));
+ }
+
+ @Test
+ public void testPrefixAtEnd() {
+ String[] input = {"abcde", "abcfgh", "abcmnop"};
+ String expected = "abc";
+ assertEquals(expected, longestCommonPrefix.longestCommonPrefix(input));
+ }
+
+ @Test
+ public void testMixedCase() {
+ String[] input = {"Flower", "flow", "flight"};
+ String expected = "";
+ assertEquals(expected, longestCommonPrefix.longestCommonPrefix(input));
+ }
+}
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