class MyQueue { public: /** Initialize your data structure here. */ MyQueue() { } /** Push element x to the back of queue. */ voidpush(int x){ s1.push(x); } /** Removes the element from in front of queue and returns that element. */ intpop(){ if(s2.empty()) { while(!s1.empty()) { s2.push(s1.top()); s1.pop(); } } int value = s2.top(); s2.pop(); return value; } /** Get the front element. */ intpeek(){ if(s2.empty()) { while(!s1.empty()) { s2.push(s1.top()); s1.pop(); } } return s2.top(); } /** Returns whether the queue is empty. */ boolempty(){ return s1.empty() && s2.empty(); }
private: stack<int> s1; stack<int> s2; };
/** * 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(); */