Add FairShareScheduling algorithm (#5815)

src/main/java/com/thealgorithms/scheduling/FairShareScheduling.java

@@ -0,0 +1,65 @@
+package com.thealgorithms.scheduling;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * FairShareScheduling allocates CPU resources equally among users or groups
+ * instead of individual tasks. Each group gets a proportional share,
+ * preventing resource hogging by a single user's processes.
+ *
+ * Use Case: Multi-user systems where users submit multiple tasks simultaneously,
+ * such as cloud environments.
+ *
+ * @author Hardvan
+ */
+public final class FairShareScheduling {
+
+    static class User {
+        String name;
+        int allocatedResources;
+        int totalWeight;
+
+        User(String name) {
+            this.name = name;
+            this.allocatedResources = 0;
+            this.totalWeight = 0;
+        }
+
+        void addWeight(int weight) {
+            this.totalWeight += weight;
+        }
+    }
+
+    private final Map<String, User> users; // username -> User
+
+    public FairShareScheduling() {
+        users = new HashMap<>();
+    }
+
+    public void addUser(String userName) {
+        users.putIfAbsent(userName, new User(userName));
+    }
+
+    public void addTask(String userName, int weight) {
+        User user = users.get(userName);
+        if (user != null) {
+            user.addWeight(weight);
+        }
+    }
+
+    public void allocateResources(int totalResources) {
+        int totalWeights = users.values().stream().mapToInt(user -> user.totalWeight).sum();
+        for (User user : users.values()) {
+            user.allocatedResources = (int) ((double) user.totalWeight / totalWeights * totalResources);
+        }
+    }
+
+    public Map<String, Integer> getAllocatedResources() {
+        Map<String, Integer> allocation = new HashMap<>();
+        for (User user : users.values()) {
+            allocation.put(user.name, user.allocatedResources);
+        }
+        return allocation;
+    }
+}