剑指offer编程题——07 两个栈实现队列

#include <iostream>
#include <exception>
#include <stack>
using namespace std;
template<typename T> class CQueue{
private:
stack<T> stack1;
stack<T> stack2;
public:
CQueue();
~CQueue();
void appendTail(const T& element);
T deleteHead();
int size();
};

template<typename T> CQueue<T>::CQueue(){};

template<typename T> CQueue<T>::~CQueue(){};

template<typename T> void CQueue<T>::appendTail(const T& element){
stack1.push(element);
}
template<typename T> T CQueue<T>::deleteHead(){
if (stack2.size() <= 0){
while (stack1.size() > 0){
T& data = stack1.top();
stack1.pop();
stack2.push(data);
}
}
if (stack2.size() == 0)
throw exception("queue is empty.");

T head = stack2.top();
stack2.pop();

return head;
}
template<typename T> int CQueue<T>::size(){
return stack1.size() + stack2.size();
}
void main07(){
CQueue<int> cq;
int elem[10] = {0};
cout << "enter order: ";
for (int i = 5; i > 0; --i){
cq.appendTail(i);
cout << i << " ";
}
cout << endl << "out order: ";
for (int i = 0; i < 5; ++i){
elem[i] = cq.deleteHead();
cout << elem[i] << " ";
}
return;
}