题解 | #用两个栈实现队列#

class Solution
{
public:
    void push(int node) {
        this->stack1.push(node);
    }

    int pop() {
        int ret;
        if(stack2.empty()){
           while(!stack1.empty()){
               stack2.push(stack1.top());
               stack1.pop(); 
           }  
        }
        ret = stack2.top();
        stack2.pop();
        return ret;
        
    }

private:
    stack<int> stack1;
    stack<int> stack2;
};