class Solution {    class Task {        public char task;        public int numTasks;    }    public int leastInterval(char[] tasks, int n) {        if (tasks.length == 0) {            return 0;        }        Map
     
       map = new HashMap<>();        for (char c : tasks) {            if (!map.containsKey(c)) {                Task t = new Task();                t.task = c;                t.numTasks = 0;                map.put(c, t);            }            map.get(c).numTasks++;        }        Queue
      
        queue = new PriorityQueue<>((t1, t2) -> t2.numTasks - t1.numTasks);        queue.addAll(map.values());        int result = 0;        while (!queue.isEmpty()) {            int k = n + 1;            List
       
         taskList = new ArrayList<>();            while (k > 0 && !queue.isEmpty()) {                Task current = queue.poll();                current.numTasks--;                taskList.add(current);                result++;                k--;            }                        for (Task task : taskList) {                if (task.numTasks > 0) {                    queue.offer(task);                }            }            if (queue.isEmpty()) break;            result += k;        }        return result;    }}