Add Preemptive Priority Scheduling Algorithm (#4323)

src/test/java/com/thealgorithms/scheduling/PreemptivePrioritySchedulingTest.java

@@ -0,0 +1,32 @@
+package com.thealgorithms.scheduling;
+
+/**
+ * Test Cases of Preemptive Priority Scheduling Algorithm
+ * @author [Bama Charan Chhandogi](https://www.github.com/BamaCharanChhandogi)
+ */
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.util.*;
+import org.junit.jupiter.api.Test;
+
+class PreemptivePrioritySchedulingTest {
+
+    @Test
+    void testPreemptivePriorityScheduling() {
+        // Arrange
+        List<Process> processes = new ArrayList<>();
+        processes.add(new Process("P1", 0, 5, 10));
+        processes.add(new Process("P2", 1, 4, 20));
+        processes.add(new Process("P3", 2, 2, 30));
+        processes.add(new Process("P4", 4, 1, 40));
+
+        List<String> expectedGanttChart = Arrays.asList("P1", "P2", "P3", "P3", "P4", "P2", "P2", "P2", "P1", "P1", "P1", "P1");
+
+        // Act
+        List<String> actualGanttChart = PreemptivePriorityScheduling.preemptivePriorityScheduling(processes);
+
+        // Assert
+        assertEquals(expectedGanttChart, actualGanttChart);
+    }
+}