Leetcode225--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 < Code style= "Font-family:menlo,monaco,consolas, ' Courier New ', monospace; font-size:12.6000003814697px; PADDING:2PX 4px; Color:rgb (199,37,78); Background-color:rgb (249,242,244) ">push to Back ,  peek/pop from front ,  size , And is empty  operations is valid.
• Depending on your language, queue May is not supported natively. You could simulate a queue by using a list or deque (double-ended queue), as long as if you have standard operations of a Q Ueue.
• You may assume this all operations is valid (for example, no pop or top operations would 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.

implementation:
Class Stack {
Public
Push element x onto stack.
void push (int x) {
Dq.push_back (x);
last = x;
}


Removes the element on top of the stack.
void Pop () {
if (empty ()) return;
Vector<int> VEC;
while (!empty ()) {
Vec.push_back (Dq.front ());
Dq.pop_front ();
}
for (int i = 0; i < vec.size ()-1; i++) {
Push (Vec[i]);
}
}


Get the top element.
int Top () {
return last;
}


Return whether the stack is empty.
bool Empty () {
return dq.size () = = 0;
}
Private
Deque<int> DQ;
int last;
};

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Leetcode225--implement Stack using Queues