题解 | #用两个栈实现队列#

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

    int pop() {
        if (stack2.empty()){   //出栈为空时把入栈所有元素放入
            while (!stack1.empty()){
                stack2.push(stack1.top());  stack1.pop();
            }
        }
        int tmp = stack2.top();  
        stack2.pop();
        return tmp;
    
    }

private:
    stack<int> stack1;  //入栈
    stack<int> stack2;  //出栈
};