Add tests for TwoSumProblem and reduce duplication (fixes #4177) (#4176)

src/test/java/com/thealgorithms/others/TwoPointersTest.java

@@ -0,0 +1,44 @@
+package com.thealgorithms.others;
+
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+
+public class TwoPointersTest {
+
+
+    @Test
+    void twoPointersFirstTestCase(){
+        int[] arr = {2,6,9,22,121};
+        int key = 28;
+        assertEquals(true, TwoPointers.isPairedSum(arr,key));
+    }
+
+    @Test
+    void twoPointersSecondTestCase(){
+        int[] arr = {-1,-12,12,0,8};
+        int key = 0;
+        assertEquals(true, TwoPointers.isPairedSum(arr,key));
+    }
+
+    @Test
+    void twoPointersThirdTestCase(){
+        int[] arr = {12,35,12,152,0};
+        int key = 13;
+        assertEquals(false, TwoPointers.isPairedSum(arr,key));
+    }
+
+    @Test
+    void twoPointersFourthTestCase(){
+        int[] arr = {-2,5,-1,52,31};
+        int key = -3;
+        assertEquals(true, TwoPointers.isPairedSum(arr,key));
+    }
+
+    @Test
+    void twoPointersFiftiethTestCase(){
+        int[] arr = {25,1,0,61,21};
+        int key = 12;
+        assertEquals(false, TwoPointers.isPairedSum(arr,key));
+    }
+}