Package g0601_0700.s0621_task_scheduler

Class Solution

java.lang.Object
g0601_0700.s0621_task_scheduler.Solution
public class Solution extends java.lang.Object
621 - Task Scheduler.

Medium

Given a characters array tasks, representing the tasks a CPU needs to do, where each letter represents a different task. Tasks could be done in any order. Each task is done in one unit of time. For each unit of time, the CPU could complete either one task or just be idle.

However, there is a non-negative integer n that represents the cooldown period between two same tasks (the same letter in the array), that is that there must be at least n units of time between any two same tasks.

Return the least number of units of times that the CPU will take to finish all the given tasks.

Example 1:

Input: tasks = [“A”,“A”,“A”,“B”,“B”,“B”], n = 2

Output: 8

Explanation: A -> B -> idle -> A -> B -> idle -> A -> B There is at least 2 units of time between any two same tasks.

Example 2:

Input: tasks = [“A”,“A”,“A”,“B”,“B”,“B”], n = 0

Output: 6

Explanation: On this case any permutation of size 6 would work since n = 0. [“A”,“A”,“A”,“B”,“B”,“B”] [“A”,“B”,“A”,“B”,“A”,“B”] [“B”,“B”,“B”,“A”,“A”,“A”] … And so on.

Example 3:

Input: tasks = [“A”,“A”,“A”,“A”,“A”,“A”,“B”,“C”,“D”,“E”,“F”,“G”], n = 2

Output: 16

Explanation: One possible solution is A -> B -> C -> A -> D -> E -> A -> F -> G -> A -> idle -> idle -> A -> idle -> idle -> A

Constraints:

  • 1 <= task.length <= 104
  • tasks[i] is upper-case English letter.
  • The integer n is in the range [0, 100].

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    leastInterval(char[] tasks, int n)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • leastInterval

      public int leastInterval(char[] tasks, int n)