用两个栈模拟队列的思想就是“倒水思想”，这里我们用自定义类型模拟出线性表，再用线性表做容器实现栈的数据结构，最后用栈来实现队列，代码如下：

#include<iostream>
#include<string>
#include<cassert>
struct __TrueType//类型萃取
{bool Get(){return true;}
};
struct __FalseType
{bool Get(){return false;}
};template <class _Tp>
struct TypeTraits
{typedef __FalseType   __IsPODType;
};template <>
struct TypeTraits< bool>
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< char>
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< unsigned char >
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< short>
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< unsigned short >
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< int>
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< unsigned int >
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< long>
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< unsigned long >
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< long long >
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< unsigned long long>
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< float>
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< double>
{typedef __TrueType     __IsPODType;
};template <>
struct TypeTraits< long double >
{typedef __TrueType     __IsPODType;
};template <class _Tp>
struct TypeTraits< _Tp*>
{typedef __TrueType     __IsPODType;
};template <class T>//自定义类型实现线性表
class SeqList
{
public:SeqList():_size(0),_capacity(10),_array(new T[_capacity]){memset(_array, 0, sizeof(T)*_capacity);}SeqList(const T &x):_size(1),_capacity(10),_array(new T[_capacity]){_array[0] = x;}SeqList(const SeqList & x){_array = new T[x._size];my_memcpy(_array, x._array, sizeof(T)*x._size);_capacity = x._size;_size = _capacity;}void PushBack(const T & x){_CheckCapacity();_array[_size++] = x;}void PushFront(const T & x){_CheckCapacity();for (size_t i = _size; i > 1; i--){_array[_size] = _array[_size - 1];}_size++;_array[0] = x;}void PopBack(){_size--;}void PopFront(){assert(_size);for (size_t i = 0; i < _size - 1; i++){_array[i] = _array[i + 1];}_size--;}size_t Size(){return _size;}SeqList & operator = (SeqList  l){swap(_array, l._array);swap(_size, l._size);swap(_capacity, l._capacity);return *this;}~SeqList(){if (_array){delete[] _array;}}T& operator [] (const size_t t){return _array[t];}
private:void _CheckCapacity(){if (_size >= _capacity){_capacity *= 3;T * tmp = new T[_capacity];memcpy(tmp, _array, sizeof(T)*_capacity);delete[] _array;_array = tmp;}}void my_memcpy(T* dst, const T* src, size_t size){if (TypeTraits <T>::__IsPODType().Get()){memcpy(dst, src, size*sizeof (T));}else{for (size_t i = 0; i < size; ++i){dst[i] = src[i];}}}size_t _size;size_t _capacity;T *_array;
};
template <class T,typename Contianer = SeqList<T> >//适配器实现栈
class Stack
{
public:void Push(const T & x){_con.PushBack(x);}void Pop(){_con.PopBack();}size_t Size(){return _con.Size();}bool Empty(){return Size() == 0;}T&top(){return _con[Size() - 1];}
protected:Contianer _con;
};
template <class T,typename container = Stack<T> >//以栈为适配器，实现队列
class Queue
{
public:bool Empty(){return (_InStack.Empty() && _OutStack().Empty());}size_t Size(){return _InStack.Size() + _OutStack.Size();}void Push(const T &x){_InStack.Push(x);}void Pop(){size_t MoveCount = _InStack.Size() - 1;for (size_t iCount = MoveCount; iCount > 0; --iCount){T temp = _InStack.top();_OutStack.Push(temp);_InStack.Pop();}_InStack.Pop();while (false == _OutStack.Empty()){T temp = _OutStack.top();_InStack.Push(temp);_OutStack.Pop();}}T& Front(){return _InStack.top();}T& Back(){size_t MoveCount = _InStack.Size() - 1;for (size_t iCount = MoveCount; iCount > 0; --iCount){T temp = _InStack.top();_OutStack.Push(temp);_InStack.Pop();}T ret = _InStack.top();while (false == _OutStack.Empty()){T temp = _OutStack.top();_Instack.Push(temp);_OutStack.Pop();}return ret;}void PrintQueue(){size_t MoveCount = _InStack.Size();for (size_t iCount = MoveCount; iCount > 0; --iCount){T temp = _InStack.top();_OutStack.Push(temp);_InStack.Pop();}while (false == _OutStack.Empty()){T temp = _OutStack.top();_InStack.Push(temp);cout << "<-" << temp;_OutStack.Pop();}cout << endl;}
private:container _InStack;container _OutStack;
};

测试用例如下：

void Test()
{Queue<int> q1;q1.Push(1);q1.Push(2);q1.Push(3);q1.Push(4);q1.Push(5);q1.Push(6);q1.PrintQueue();q1.Pop();q1.PrintQueue();}

如有什么不足或疑问，希望指教