}/** Removes the element from in front of queue and returns that element. */publicintpop(){returnstack.pop(); }/** Get the front element. */publicintpeek(){inta = stack.pop(); stack.push(a);returna; }/** Returns whether the queue is empty. */publicbooleanempty(){returnstack.i...
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. Notes: You must use only standard operations of a stack -- which means only push to top, peek...
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. Notes: You must use only standard oper...
class MyQueue: def __init__(self): self.stack_in = [] self.stack_out = [] def push(self, x: int) -> None: self.stack_in.append(x) def pop(self) -> int: if self.empty(): return None if self.stack_out: return self.stack_out.pop() else: for _ in range(len(self.stack...
代码(Java): classMyQueue{privateStack<Integer>in=newStack<>();privateStack<Integer>out=newStack<>();// Push element x to the back of queue.publicvoidpush(intx){in.push(x);}// Removes the element from in front of queue.publicvoidpop(){while(!in.empty()){out.push(in.pop());}ou...
public MyQueue() { in = new Stack<>(); out = new Stack<>(); } /** Push element x to the back of queue. */ public void push(int x) { in.push(x); } /** Removes the element from in front of queue and returns that element. */ ...
思路:Queue是先进先出FIFO,Stack是先进后出FILO。使用Stack模拟实现Queue的功能,可以使用两个Stack,一个进行入Stack操作,一个进行出Stack操作。这两个Stack中的元素位置是颠倒的。比如,一个元素在第一个Stack位于Stack头,那么这个元素在另一个Stack则位于Stack尾。
Java程序 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. ...
importjava.util.LinkedList;importjava.util.Queue;classMyStack{privateQueue<Integer>queue_1=newLinkedList<>();privateQueue<Integer>queue_2=newLinkedList<>();privateint top;/** Initialize your data structure here. */publicMyStack(){}/** Push element x onto stack. */publicvoidpush(int x){queu...
Dequeue an element from the queue. C++ Java Python #include<bits/stdc++.h> using namespace std; class Stack { queue<int>q; public: void push(int val); void pop(); int top(); bool empty(); }; void Stack::push(int val) { int s = q.size(); q.push(val); for (int i=0...