题解 | #用两个栈实现队列#

class Solution
{
public:
    void push(int node) {
        stack1.push(node);
    }
    int pop() {
        while (stack1.size() != 1) {
            stack2.push(stack1.top());
            stack1.pop();
        }
        int ans = stack1.top();
        stack1.pop();
        while (stack2.size()) {
            stack1.push(stack2.top());
            stack2.pop();
        }
        return ans;
    }

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