Greedy

Task scheduler problem

1. Intuitive: construct string from left to right. Use priority queue to firstly consume most frequent char. When a char is used, it has to wait k time to join the pool again. O(Nlog26) time -> O(N).

• 0358. Rearrange String k Distance Apart

1. Visualization: get most frequent char, fill each slot, e.g. A B ? ? A B ? ? A B

• 0621. Task Scheduler

• 0767. Reorganize String