From 2c1ec6c272cf71246d0d09275b8a35293b78d41e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ozan=20=C3=96zayranci?=
 <38402864+oozan@users.noreply.github.com>
Date: Wed, 22 Jul 2026 18:23:50 +0300
Subject: [PATCH 1/3] fix: reject negative input in SumOfSquares

---
 src/main/java/com/thealgorithms/maths/SumOfSquares.java | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/main/java/com/thealgorithms/maths/SumOfSquares.java b/src/main/java/com/thealgorithms/maths/SumOfSquares.java
index c050d5a75f7b..e9022271d454 100644
--- a/src/main/java/com/thealgorithms/maths/SumOfSquares.java
+++ b/src/main/java/com/thealgorithms/maths/SumOfSquares.java
@@ -18,8 +18,13 @@ private SumOfSquares() {
      *
      * @param n the target number
      * @return minimum number of squares needed
+     * @throws IllegalArgumentException if {@code n} is negative
      */
     public static int minSquares(int n) {
+        if (n < 0) {
+            throw new IllegalArgumentException("Input must be non-negative");
+        }
+
         if (isPerfectSquare(n)) {
             return 1;
         }

From 6c09d56a6243735b111231c59521014845fbbc57 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ozan=20=C3=96zayranci?=
 <38402864+oozan@users.noreply.github.com>
Date: Wed, 22 Jul 2026 18:23:52 +0300
Subject: [PATCH 2/3] test: cover negative SumOfSquares input

---
 .../java/com/thealgorithms/maths/SumOfSquaresTest.java    | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/test/java/com/thealgorithms/maths/SumOfSquaresTest.java b/src/test/java/com/thealgorithms/maths/SumOfSquaresTest.java
index 834fe61a049e..98674d05708c 100644
--- a/src/test/java/com/thealgorithms/maths/SumOfSquaresTest.java
+++ b/src/test/java/com/thealgorithms/maths/SumOfSquaresTest.java
@@ -1,6 +1,7 @@
 package com.thealgorithms.maths;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import org.junit.jupiter.api.Test;
 
@@ -63,6 +64,11 @@ void testLargerNumbers() {
     @Test
     void testEdgeCases() {
         // Test edge case
-        assertEquals(1, SumOfSquares.minSquares(0)); // 0^2
+    
+    @Test
+    void testNegativeInput() {
+        assertThrows(IllegalArgumentException.class, () -> SumOfSquares.minSquares(-1));
+    }
+    assertEquals(1, SumOfSquares.minSquares(0)); // 0^2
     }
 }

From 90cb3eb7af32174b51ab6c2dea263afa9c47cb8f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ozan=20=C3=96zayranci?=
 <38402864+oozan@users.noreply.github.com>
Date: Wed, 22 Jul 2026 18:30:57 +0300
Subject: [PATCH 3/3] fix: correct SumOfSquares test structure

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

diff --git a/src/test/java/com/thealgorithms/maths/SumOfSquaresTest.java b/src/test/java/com/thealgorithms/maths/SumOfSquaresTest.java
index 98674d05708c..03f9d60c9385 100644
--- a/src/test/java/com/thealgorithms/maths/SumOfSquaresTest.java
+++ b/src/test/java/com/thealgorithms/maths/SumOfSquaresTest.java
@@ -64,11 +64,11 @@ void testLargerNumbers() {
     @Test
     void testEdgeCases() {
         // Test edge case
-    
+        assertEquals(1, SumOfSquares.minSquares(0)); // 0^2
+    }
+
     @Test
     void testNegativeInput() {
         assertThrows(IllegalArgumentException.class, () -> SumOfSquares.minSquares(-1));
     }
-    assertEquals(1, SumOfSquares.minSquares(0)); // 0^2
-    }
 }