摘要： Link: https://leetcode.com/problems/min-stack/ Constraint: Idea We could use two stacks, one responsible for regular stack operations; the other one r 阅读全文

摘要： https://leetcode.com/problems/implement-stack-using-queues/ ##Code 阅读全文

摘要： Link: https://leetcode.com/problems/implement-queue-using-stacks/ Constaints 1 <= x <= 9 At most 100 calls will be made to push, pop, peek, and empty. 阅读全文