【leetcode】Implement Queue using Stacks
来源:互联网 发布:化学分析软件 编辑:程序博客网 时间:2024/05/01 06:13
Implement Queue using Stacks
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.
Notes:
You must use only standard operations of a stack – which means only push to top, peek/pop from top, size, and is 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).
思路:
堆栈a和b,a用作入队,b出队
(1)判队满:如果a满且b不为空,则队满
(2)判队空:如果a和b都为空,则队空
(3)入队:首先判队满。
若队不满:(1)栈a若不满,则直接压入栈a
(2)若a满,则将a中的所有元素弹出到栈b中,然后再将元素入栈a
(4)出队:(1)若b空就将a中的所有元素弹出到栈b中,然后出栈
(2)b不空就直接从b中弹出元素
class Queue {public: stack<int> in; stack<int> out; // Push element x to the back of queue. void push(int x) { in.push(x); } void move(){ while(!in.empty()) { int x = in.top(); in.pop(); out.push(x); } } // Removes the element from in front of queue. void pop(void) { if(out.empty()) { move(); } if(!out.empty()) { out.pop(); } } // Get the front element. int peek(void) { if(out.empty()) { move(); } if(!out.empty()) { return out.top(); } } // Return whether the queue is empty. bool empty(void) { return in.empty() && out.empty(); }};
http://blog.csdn.net/sunao2002002/article/details/46793425
- 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
- LightOJ_1422_HalloweenCostumes
- iOS绘制效果界面
- C++函数
- 黑马程序员——Java学习笔记——数组的排序和查找
- cassandra counter 类型使用注意事项
- 【leetcode】Implement Queue using Stacks
- Laravel资料总结
- 242-e-Valid Anagram
- Java验证码读取
- 高清屏的背景图片适配
- C++ 常见面试题目 (二)
- JQuery隐藏,显示div的方法
- [objective-c]获取ip地址
- C语言编程入门——指针(下)