【学习点滴-数据结构-栈&队列】 用两个队列模拟一个栈

题目描述：用两个队列模拟一个栈。栈和队列的实现源码已经给出。

本文系转载。

原文地址：http://blog.csdn.net/wangyangkobe/article/details/5910362

@wangyangkobe

#include <cstdlib>#include <iostream>#include <assert.h>#include <deque>using namespace std;/*两个队列模拟一个堆栈*//*队列A、B入栈：将元素依次压入到非空的队列，第一个元素压倒对列A出栈：把队列A的前n-1个元素倒到队列B，把第n个元素去掉。此时数据在B中，下次操作，则对B操作。栈顶：把队列A的前n-1个元素倒到队列B，把第n个元素作为栈顶*/template <typename T>class MyStack{public://入栈，第一个元素进到队列deque1，以后每个元素进到非空的队列void  push(T element){if (deque1.empty() && deque2.empty()){deque1.push_back(element);}else if (!deque1.empty() && deque2.empty()){deque1.push_back(element);}else if (deque1.empty() && !deque2.empty()){deque2.push_back(element);}}//出栈，将非空队列的前n-1个元素转移到另一个空的队列，删除非空队列的第n个元素void pop(){if (!deque1.empty()){int size = deque1.size();for (int i=0; i<size-1; i++){deque2.push_back(deque1.front());deque1.pop_front();}deque1.pop_front();}else{int size = deque2.size();for (int i=0; i<size-1; i++){deque1.push_back(deque2.front());deque2.pop_front();}deque2.pop_front();}}//栈顶元素，将非空队列的前n-1个元素转移到另一个空的队列，将非空队列的第n个元素返回T top(){if (!deque1.empty()){int size = deque1.size();for (int i=0; i<size-1; i++){deque2.push_back(deque1.front());deque1.pop_front();}T temp = deque1.front();deque1.pop_front();deque2.push_back(temp);return temp;}else{int size = deque2.size();for (int i=0; i<size-1; i++){deque1.push_back(deque2.front());deque2.pop_front();}T temp = deque2.front();deque2.pop_front();deque1.push_back(temp);return temp;}}//栈是否为空bool empty(){return (deque1.empty()&&deque2.empty());}private:deque<T> deque1;deque<T> deque2;};int main(int argc, char *argv[]){MyStack<int> my;for (int i=0; i<10; i++){my.push(i);}while (!my.empty()){cout<<my.top()<<" ";my.pop();}cout<<endl;}