题解 | #用两个栈实现队列#

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

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

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