LeetCode-Implement Queue using Stacks
来源:互联网 发布:淘宝首页html代码示例 编辑:程序博客网 时间:2024/04/18 18:12
Implement the following operations of a queue using stacks.
- push(x) -- Push element x to the back of queue.
- pop() -- Removes the element from in front of queue.
- peek() -- Get the front element.
- empty() -- Return whether the queue is empty.
- You must use only standard operations of a stack -- which means only
push to top
,peek/pop from top
,size
, andis empty
operations are valid. - Depending on your language, stack may not be supported natively. You may simulate a stack by using a list or deque (double-ended queue), as long as you use only standard operations of a stack.
- You may assume that all operations are valid (for example, no pop or peek operations will be called on an empty queue).
class MyQueue { LinkedList<Integer> stack1 = new LinkedList<Integer>(); LinkedList<Integer> stack2 = new LinkedList<Integer>(); // Push element x to the back of queue. public void push(int x) { stack1.push(x); } // Removes the element from in front of queue. public void pop() { if (stack2.isEmpty()) { while (!stack1.isEmpty()) { stack2.push(stack1.pop()); } } stack2.pop(); } // Get the front element. public int peek() { if (stack2.isEmpty()) { while (!stack1.isEmpty()) { stack2.push(stack1.pop()); } } return stack2.peek(); } // Return whether the queue is empty. public boolean empty() { return stack1.isEmpty() && stack2.isEmpty(); }}
0 0
- leetcode :Implement Queue using Stacks
- [LeetCode] Implement Queue using Stacks
- LeetCode Implement Queue using Stacks
- LeetCode || Implement Queue using Stacks
- leetcode Implement Queue using Stacks
- Leetcode Implement Queue using Stacks
- [LeetCode]Implement Queue using Stacks
- 【Leetcode】Implement Queue using Stacks
- LeetCode Implement Queue using Stacks
- Leetcode: Implement Queue using Stacks
- [leetcode] Implement Queue using Stacks
- 【leetcode】Implement Queue using Stacks
- [Leetcode]Implement Queue using Stacks
- [leetcode] Implement Queue using Stacks
- LeetCode-Implement Queue using Stacks
- LeetCode Implement Queue using Stacks
- Leetcode: Implement Queue using Stacks
- LeetCode:Implement Queue using Stacks
- 【Spring笔记】
- hdu 5384 Danganronpa 2015多校联合训练赛#8 ac自动机
- OC 找出在只有空格字母的字符串中出现次数最多的单词
- HDU 5365
- C++ sizeof 和strlen
- LeetCode-Implement Queue using Stacks
- Linux2.6.38内核启动流程分析
- sys.argv
- 斐波那契数列
- 【Android实战】使用帧动画实现自定义loading加载布局
- Scala练习(十)
- 素数筛选 模版
- 线程 ,生产者. 消费者 互斥锁,条件变量
- 导航控制器---UINavigationController