两个队列模拟栈

#include<queue>
#include<iostream>
using namespace std;
template<typename T>
class CStack
{
public:
CStack(){};
~CStack(){};
void append(const T& node);
T deleteHead();
private:
queue<T> queue1,queue2;
};
template<typename T>
void CStack<T>::append(const T& node)
{
queue1.push(node);
}
template<typename T>
T CStack<T>::deleteHead()
{
T node,node1;
while(queue1.size()>1){
node=queue1.front();
queue1.pop();
queue2.push(node);
}
if(queue1.size()!=1) throw "empty";
node1=queue1.front();
queue1.pop();
while(!queue2.empty())
{
node=queue2.front();
queue2.pop();
queue1.push(node);
}
return node1;
}
int main()
{
CStack<int> cs;
cs.append(3);
cs.append(4);
try{
cout<<cs.deleteHead()<<endl;
cout<<cs.deleteHead()<<endl;
cout<<cs.deleteHead()<<endl;
}catch(const char* str)
{
cout<<str<<endl;
}
return 0;
}