You're given a list of tasks, with number denoted different type of tasks, and there'll be interval between tasks with tasks of same id. Return total time for executing this task list.

Example:

Input: tasks = [1, 1, 2, 1], interval = 2
Output: 7
Expalanation:
It's executed as 1 . . 1 2 . 1, so the total time is 7.

Related problems:

• https://leetcode.com/problems/task-scheduler/