题解 | #用两个栈实现队列#

/*
使用stack1作为正常栈，stack2作为输出栈
*/
class Solution
{
public:
    void push(int node) {
        stack1.push(node);
        
    }

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

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