Add FairShareScheduling algorithm (#5815)

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

@@ -0,0 +1,60 @@
+package com.thealgorithms.scheduling;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Map;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class FairShareSchedulingTest {
+
+    private FairShareScheduling scheduler;
+
+    @BeforeEach
+    public void setup() {
+        scheduler = new FairShareScheduling();
+    }
+
+    @Test
+    public void testAllocateResourcesSingleUser() {
+        scheduler.addUser("User1");
+        scheduler.addTask("User1", 5);
+        scheduler.allocateResources(100);
+        Map<String, Integer> expected = Map.of("User1", 100);
+        assertEquals(expected, scheduler.getAllocatedResources());
+    }
+
+    @Test
+    public void testAllocateResourcesMultipleUsers() {
+        scheduler.addUser("User1");
+        scheduler.addUser("User2");
+        scheduler.addUser("User3");
+        scheduler.addTask("User1", 2);
+        scheduler.addTask("User2", 3);
+        scheduler.addTask("User3", 5);
+        scheduler.allocateResources(100);
+        Map<String, Integer> expected = Map.of("User1", 20, "User2", 30, "User3", 50);
+        assertEquals(expected, scheduler.getAllocatedResources());
+    }
+
+    @Test
+    public void testAllocateResourcesZeroWeightUser() {
+        scheduler.addUser("User1");
+        scheduler.addUser("User2");
+        scheduler.addTask("User2", 5);
+        scheduler.allocateResources(100);
+        Map<String, Integer> expected = Map.of("User1", 0, "User2", 100);
+        assertEquals(expected, scheduler.getAllocatedResources());
+    }
+
+    @Test
+    public void testAllocateResourcesEqualWeights() {
+        scheduler.addUser("User1");
+        scheduler.addUser("User2");
+        scheduler.addTask("User1", 1);
+        scheduler.addTask("User2", 1);
+        scheduler.allocateResources(100);
+        Map<String, Integer> expected = Map.of("User1", 50, "User2", 50);
+        assertEquals(expected, scheduler.getAllocatedResources());
+    }
+}