Add GangScheduling algorithm (#5819)

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

@@ -0,0 +1,61 @@
+package com.thealgorithms.scheduling;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * GangScheduling groups related tasks (gangs) to run simultaneously on multiple processors.
+ * All tasks in a gang are executed together or not at all.
+ *
+ * Use Case: Parallel computing environments where multiple threads of a program
+ * need to run concurrently for optimal performance.
+ *
+ * @author Hardvan
+ */
+public final class GangScheduling {
+
+    static class Gang {
+        String name;
+        List<String> tasks;
+
+        Gang(String name) {
+            this.name = name;
+            this.tasks = new ArrayList<>();
+        }
+
+        void addTask(String task) {
+            tasks.add(task);
+        }
+
+        List<String> getTasks() {
+            return tasks;
+        }
+    }
+
+    private final Map<String, Gang> gangs;
+
+    public GangScheduling() {
+        gangs = new HashMap<>();
+    }
+
+    public void addGang(String gangName) {
+        gangs.putIfAbsent(gangName, new Gang(gangName));
+    }
+
+    public void addTaskToGang(String gangName, String task) {
+        Gang gang = gangs.get(gangName);
+        if (gang != null) {
+            gang.addTask(task);
+        }
+    }
+
+    public Map<String, List<String>> getGangSchedules() {
+        Map<String, List<String>> schedules = new HashMap<>();
+        for (Gang gang : gangs.values()) {
+            schedules.put(gang.name, gang.getTasks());
+        }
+        return schedules;
+    }
+}