题解 | 用两个栈实现队列

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

    int pop() {
        int res = -1;
        if(stack2.empty())
        {
            while(!stack1.empty())
        {
            int temp=stack1.top();
            stack2.push(temp);
            stack1.pop();
        }
        }
        res=stack2.top();
        stack2.pop();
        return res;
    }

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