From 6f61e2792c9d0c343db19e96e1cee0a4004e85dd Mon Sep 17 00:00:00 2001
From: Swati Kumari <swatijha1803@gmail.com>
Date: Sat, 3 Jan 2026 09:48:34 +0530
Subject: [PATCH 1/4] Add GCDUsingEuclid class to compute GCD

Implemented the Euclidean algorithm for GCD calculation.
---
 .../thealgorithms/maths/GCDUsingEuclid.java   | 38 +++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 src/main/java/com/thealgorithms/maths/GCDUsingEuclid.java

diff --git a/src/main/java/com/thealgorithms/maths/GCDUsingEuclid.java b/src/main/java/com/thealgorithms/maths/GCDUsingEuclid.java
new file mode 100644
index 000000000000..36219bfd951b
--- /dev/null
+++ b/src/main/java/com/thealgorithms/maths/GCDUsingEuclid.java
@@ -0,0 +1,38 @@
+package com.thealgorithms.maths;
+
+/**
+ * Euclidean algorithm to compute the Greatest Common Divisor (GCD).
+ * Wikipedia: https://en.wikipedia.org/wiki/Euclidean_algorithm
+ */
+public final class GCDUsingEuclid {
+
+    private GCDUsingEuclid() {
+        // Utility class
+    }
+
+    /**
+     * Computes GCD of two integers using Euclidean algorithm.
+     *
+     * @param a first integer
+     * @param b second integer
+     * @return gcd(a, b)
+     */
+    public static int gcd(int a, int b) {
+        a = Math.abs(a);
+        b = Math.abs(b);
+
+        if (a == 0) {
+            return b;
+        }
+        if (b == 0) {
+            return a;
+        }
+
+        while (b != 0) {
+            int remainder = a % b;
+            a = b;
+            b = remainder;
+        }
+        return a;
+    }
+}

From 4b6a44d3a52f2274743834f00b212bebee6bb02f Mon Sep 17 00:00:00 2001
From: Swati Kumari <swatijha1803@gmail.com>
Date: Sat, 3 Jan 2026 09:49:50 +0530
Subject: [PATCH 2/4] Implement unit tests for GCDUsingEuclid

Add unit tests for GCDUsingEuclid class covering positive, zero, and negative numbers.
---
 .../maths/GCDUsingEuclidTest.java             | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java

diff --git a/src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java b/src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java
new file mode 100644
index 000000000000..e2eb1a28c278
--- /dev/null
+++ b/src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java
@@ -0,0 +1,25 @@
+package com.thealgorithms.maths;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.Test;
+
+class GCDUsingEuclidTest {
+
+    @Test
+    void testPositiveNumbers() {
+        assertEquals(6, GCDUsingEuclid.gcd(54, 24));
+        assertEquals(1, GCDUsingEuclid.gcd(17, 13));
+    }
+
+    @Test
+    void testWithZero() {
+        assertEquals(5, GCDUsingEuclid.gcd(0, 5));
+        assertEquals(7, GCDUsingEuclid.gcd(7, 0));
+    }
+
+    @Test
+    void testNegativeNumbers() {
+        assertEquals(4, GCDUsingEuclid.gcd(-8, 12));
+        assertEquals(9, GCDUsingEuclid.gcd(-9, -18));
+    }
+}

From 159a709df963be8d210600dd7b07ab538b81ad7d Mon Sep 17 00:00:00 2001
From: Swati Kumari <swatijha1803@gmail.com>
Date: Sat, 3 Jan 2026 10:15:14 +0530
Subject: [PATCH 3/4] Reorder import statement for assertEquals

---
 src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java b/src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java
index e2eb1a28c278..0a91d58532f9 100644
--- a/src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java
+++ b/src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java
@@ -1,8 +1,9 @@
 package com.thealgorithms.maths;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 class GCDUsingEuclidTest {
 
     @Test

From 132dbd626a960f064316bc459f092babdf7cb053 Mon Sep 17 00:00:00 2001
From: Swati Kumari <swatijha1803@gmail.com>
Date: Sat, 3 Jan 2026 10:45:47 +0530
Subject: [PATCH 4/4] Update GCDUsingEuclidTest.java

---
 .../java/com/thealgorithms/maths/GCDUsingEuclidTest.java    | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java b/src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java
index 0a91d58532f9..4ae98528ece7 100644
--- a/src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java
+++ b/src/test/java/com/thealgorithms/maths/GCDUsingEuclidTest.java
@@ -1,10 +1,10 @@
 package com.thealgorithms.maths;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-class GCDUsingEuclidTest {
+import org.junit.jupiter.api.Test;
+
+public class GCDUsingEuclidTest {
 
     @Test
     void testPositiveNumbers() {