225.Implement Stack using Queues

Implement the following operations of a stack using queues.
push(x) -- Push element x onto stack.
pop() -- Removes the element on top of the stack.
top() -- Get the top element.
empty() -- Return whether the stack is empty.
Notes:
You must use only standard operations of a queue -- which means only 

push
to back

, 

peek/pop from front

, 

size

,
and 

is empty

 operations are valid.
Depending on your language, queue may not be supported natively. You may simulate a queue by using a list or deque (double-ended queue), as long as you use only standard operations of a queue.
You may assume that all operations are valid (for example, no pop or top operations will be called on an empty stack).

Update (2015-06-11):

The class name of the Java function had been updated to MyStack instead of Stack.

Credits:

Special thanks to @jianchao.li.fighter for adding this problem and all test cases.

class Stack {
private:
queue<int> myQueue1;
queue<int> myQueue2;
public:
// Push element x onto stack.
void push(int x) {
myQueue1.push(x);

}

// Removes the element on top of the stack.
void pop() {
int eleNum = myQueue1.size();
while(eleNum > 1)
{
myQueue2.push(myQueue1.front());
myQueue1.pop();
eleNum--;
}
myQueue1.pop();

eleNum = myQueue2.size();
while(eleNum > 0)
{
myQueue1.push(myQueue2.front());
myQueue2.pop();
eleNum--;
}

}

// Get the top element.
int top() {
int eleNum = myQueue1.size();
while(eleNum > 1)
{
myQueue2.push(myQueue1.front());
myQueue1.pop();
eleNum--;
}

int ret = myQueue1.front();

myQueue2.push(myQueue1.front());
myQueue1.pop();

eleNum = myQueue2.size();
while(eleNum > 0)
{
myQueue1.push(myQueue2.front());
myQueue2.pop();
eleNum--;
}

return ret;

}

// Return whether the stack is empty.
bool empty() {

return myQueue1.empty();
}
};