Added jUnit for 'merge' method in class MergeIntervals

Version junit.jupiter: 5.8.1

Author: quangrandz

src/main/java/com/leetcode/arrays/MergeIntervalsTestCase.java

@@ -0,0 +1,85 @@
+package com.leetcode.arrays;
+
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+/**
+*
+* @author: quangrandz
+* @since: 2023-6-30
+*/
+
+public class MergeIntervalsTestCase {
+	
+	@BeforeAll
+    public static void beforeAll() {
+        System.out.println("BEFORE ALL");
+    }
+    
+    @AfterAll
+    public static void afterAll() {
+        System.out.println("AFTER ALL");
+    }
+    
+    @BeforeEach
+    public void beforeEach() {
+        System.out.println("BEFORE EACH");
+    }
+    
+    @AfterEach
+    public void afterEach() {
+        System.out.println("AFTER EACH");
+    }
+	
+	// Test case 1: Non-overlapping intervals
+	@Test
+	public void testMerge_NonOverlapping() {
+		int[][] intervals = {{1, 3}, {4, 6}, {7, 9}};
+        int[][] expected = {{1, 3}, {4, 6}, {7, 9}};
+        Assertions.assertArrayEquals(expected, MergeIntervals.merge(intervals));
+	}
+	
+	// Test case 2: Overlapping intervals
+	@Test
+	public void testMerge_Overlapping() {
+		int[][] intervals = {{1, 4}, {2, 5}, {6, 8}};
+        int[][] expected = {{1, 5}, {6, 8}};
+        Assertions.assertArrayEquals(expected, MergeIntervals.merge(intervals));
+	}
+	
+	// Test case 3: Empty input
+	@Test
+	public void testMerge_EmptyInput() {
+		int[][] intervals = {};
+        int[][] expected = {};
+        Assertions.assertArrayEquals(expected, MergeIntervals.merge(intervals));
+	}
+	
+	// Test case 4: Single interval
+	@Test
+	public void testMerge_SingleInterval() {
+		int[][] intervals = {{2, 6}};
+        int[][] expected = {{2, 6}};
+        Assertions.assertArrayEquals(expected, MergeIntervals.merge(intervals));
+	}
+	
+	// Test case 5: Overlapping intervals with different orders
+	@Test
+	public void testMerge_DifferentOrders() {
+		int[][] intervals = {{9, 12}, {1, 4}, {6, 8}, {2, 5}};
+        int[][] expected = {{1, 5}, {6, 8}, {9, 12}};
+        Assertions.assertArrayEquals(expected, MergeIntervals.merge(intervals));
+	}
+
+	// Test case 6: There are many overlapping time periods
+	@Test
+	public void testMerge_ManyOverlapping() {
+		int[][] intervals = {{1, 4}, {2, 5}, {3, 8}, {6, 9}};
+	    int[][] expected = {{1, 9}};
+	    Assertions.assertArrayEquals(expected, MergeIntervals.merge(intervals));
+	}
+}