returnqueue1.empty() && queue2.empty(); } }; 其他解法: 【两个队列】用两个队列myStack,temp实现一个栈。push时把新元素添加到myStack的队尾。pop时把myStack中除最后一个元素外逐个添加到myStack中,然后pop掉myStack中的最后一个元素,然后注意记得myStack和temp,以保证我们添加元素时始终向temp中添加。
Implement the following operations of a queue using stacks. push(x) -- Push element x to the back of queue. pop() -- Removes the element from in front of queue. peek() -- Get the front element. empty() -- Return whether the queue is empty. 1classMyQueue {23privateStack<Integer>s...
The STACK, the QUEUE and the DEQUE 在一个堆我们只能从一端添加和删除元素(生命力),在一个队列我们将元素添加到一端并将其从另一端删除(先进先出),然后加入这两个世界,双端队列(又名“双端队列”),我们可以在两端添加和删除元素。它们都不允许随机访问元素...
Depending on your language, the queue may not be supported natively. You may simulate a queue using a list or deque (double-ended queue) as long as you use only a queue's standard operations. Example 1: Input ["MyStack", "push", "push", "top", "pop", "empty"] [[], [1], [...
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 Depending on your language, queue may not be supported natively. You may simulate a queue by using a...
MyStack stack=newMyStack();stack.push(1);stack.push(2);();// returns 2stack.pop();// returns 2stack.empty();// returns false 1. 2. 3. 4. 5. 6. 7. Note: You must use only standard operations of a queue – which means only push to back, peek/pop from front, size, and...
You must use only standard operations of a stack -- which means only push to top, peek/pop from top, size, and is empty operations are valid. Depending on your language, stack may not be supported natively. You may simulate a stack by using a list or deque (double-ended queue), as...
myStack.pop(); // return 2 myStack.empty(); // return False Constraints: 1 <= x <= 9 At most 100 calls will be made to push, pop, top, and empty. All the calls to pop and top are valid. Follow-up: Can you implement the stack using only one queue? For questions of the ...
(self):"""Initialize your data structure here."""# 声明两个队列,由于模拟栈self.queue1 = deque()self.queue2 = deque()# self._empty指向当前空的队列self._empty = self.queue1# self._filled指向当前有填充的队列self._filled = self.queue2def push(self, x):"""Push element x onto stack....
Depending on your language, stack may not be supported natively. You may simulate a stack by using a list or deque (double-ended queue), as long as you use only standard operations of a stack. You may assume that all operations are valid (for example, no pop or peek operations will be...