定义栈的数据结构，请在该类型中实现一个能够得到栈中所含最小元素的min函数（时间复杂度应为O（1））。

import java.util.Stack;

public class Solution {
    Stack<Integer> stack = new Stack<Integer>();
    
    public void push(int node) {
        stack.push(node);
    }
    
    public void pop() {
        stack.pop();
    }
    
    public int top() {
        return stack.peek();
    }
    
    public int min() {
        Stack<Integer> temp = new Stack<Integer>();
        int min = Integer.MAX_VALUE;
        while(!stack.isEmpty()) {
            int top = stack.pop();;
            if(min > top) {
                min = top;
            }
            temp.push(top);
        }
        while(!temp.isEmpty()) {
            stack.push(temp.pop());
        }
        return min;
    }
}