题解 | #包含min函数的栈#

import java.util.*;

public class Solution {

    Stack<Integer> stack1 = new Stack<Integer>();
    Stack<Integer> stack2 = new Stack<Integer>();
    public void push(int node) {
        stack1.push(node);
    }

    public void pop() {
        stack1.pop();
    }

    public int top() {
        return stack1.peek();
    }

    public int min() {

        List<Integer> list = new ArrayList<>();
        while (!stack1.isEmpty()) {
            Integer pop = stack1.pop();
            stack2.push(pop);
            list.add(pop);
        }

        while (!stack2.isEmpty()) {
            stack1.push(stack2.pop());
        }

        return Collections.min(list);
    }
}