用兩個棧實作一個隊列的功能

#include <iostream>

#include <stack>

using namespace std;

template<class T>

struct MyQueue

{

void push(T &t)

{

s1.push(t);

}

T front()

{

if(s2.empty())

{

if(s1.size() == 0) throw;

while(!s1.empty())

{

s2.push(s1.top());

s1.pop();

}

}

return s2.top();

}

void pop()

{

if(s2.empty())

{

while(!s1.empty())

{

s2.push(s1.top());

s1.pop();

}

}

if(!s2.empty())

s2.pop();

}

stack<T> s1;

stack<T> s2;

};

int main()

{

MyQueue<int> mq;

int i;

for( i = 0; i < 10; i++ )

{

mq.push(i);

}

for( i = 0; i < 10; i++ )

{

cout<<mq.front()<<endl;

mq.pop();

}

return 0;

}