学步园

#include <cstdlib><br /> #include <iostream><br /> #include <assert.h><br /> #include <deque><br /> using namespace std;<br /> /*两个队列模拟一个堆栈*/<br /> /*队列A、B<br /> 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<br /> 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。<br /> 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*/<br /> template <typename T><br /> class MyStack<br /> {<br /> public:<br /> //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<br /> void push(T element)<br /> {<br /> if (deque1.empty() && deque2.empty())<br /> {<br /> deque1.push_back(element);<br /> }<br /> else if (!deque1.empty() && deque2.empty())<br /> {<br /> deque1.push_back(element);<br /> }<br /> else if (deque1.empty() && !deque2.empty())<br /> {<br /> deque2.push_back(element);<br /> }<br /> }<br /> //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<br /> void pop()<br /> {<br /> if (!deque1.empty())<br /> {<br /> int size = deque1.size();<br /> for (int i=0; i<size-1; i++)<br /> {<br /> deque2.push_back(deque1.front());<br /> deque1.pop_front();<br /> }<br /> deque1.pop_front();<br /> }<br /> else<br /> {<br /> int size = deque2.size();<br /> for (int i=0; i<size-1; i++)<br /> {<br /> deque1.push_back(deque2.front());<br /> deque2.pop_front();<br /> }<br /> deque2.pop_front();<br /> }<br /> }<br /> //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<br /> T top()<br /> {<br /> if (!deque1.empty())<br /> {<br /> int size = deque1.size();<br /> for (int i=0; i<size-1; i++)<br /> {<br /> deque2.push_back(deque1.front());<br /> deque1.pop_front();<br /> }<br /> T temp = deque1.front();<br /> deque1.pop_front();<br /> deque2.push_back(temp);<br /> return temp;<br /> }<br /> else<br /> {<br /> int size = deque2.size();<br /> for (int i=0; i<size-1; i++)<br /> {<br /> deque1.push_back(deque2.front());<br /> deque2.pop_front();<br /> }<br /> T temp = deque2.front();<br /> deque2.pop_front();<br /> deque1.push_back(temp);<br /> return temp;<br /> }<br /> }<br /> //栈是否为空<br /> bool empty()<br /> {<br /> return (deque1.empty()&&deque2.empty());<br /> }<br /> private:<br /> deque<T> deque1;<br /> deque<T> deque2;<br /> };<br /> int main(int argc, char *argv[])<br /> {<br /> MyStack<int> my;<br /> for (int i=0; i<10; i++)<br /> {<br /> my.push(i);<br /> }<br /> while (!my.empty())<br /> {<br /> cout<<my.top()<<" ";<br /> my.pop();<br /> }<br /> cout<<endl;<br /> }<br />