LeetCode 232. 用棧實現佇列
阿新 • • 發佈:2019-01-07
程式碼:
class MyQueue { public: /** Initialize your data structure here. */ stack<int> s1, s2; MyQueue() { } /** Push element x to the back of queue. */ void push(int x) { while(!s2.empty()) { s1.push(s2.top()); s2.pop(); } s2.push(x); while(!s1.empty()) { s2.push(s1.top()); s1.pop(); } } /** Removes the element from in front of queue and returns that element. */ int pop() { int a = s2.top(); s2.pop(); return a; } /** Get the front element. */ int peek() { return s2.top(); } /** Returns whether the queue is empty. */ bool empty() { return s2.empty(); } }; /** * Your MyQueue object will be instantiated and called as such: * MyQueue obj = new MyQueue(); * obj.push(x); * int param_2 = obj.pop(); * int param_3 = obj.peek(); * bool param_4 = obj.empty(); */