leetcode 232.用栈实现队列

class MyQueue {
public:
    MyQueue() {
        
    }
    stack<int> in;
    stack<int> out;
    
    void push(int x) {
        in.push(x);
    }
    
    int pop() {

        if(out.empty()){
            while(!in.empty()){
                int temp=in.top();
                in.pop();
                out.push(temp);
            }
        }

        int temp1=out.top();
        out.pop();
        return temp1;
    }
    
    int peek() {
        int res=this->pop();
        out.push(res);
        return res;
    }
    
    bool empty() {
        if(out.empty()&&in.empty()){
            return true;
        }else{
            return false;
        }
    }


};

/**
 * 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();
 */