题解 | #包含 min 函数的栈#

import java.util.Stack;

public class Solution {
    Stack<Integer> stack1 = new Stack<Integer>();
    Stack<Integer> stack2 = new Stack<Integer>();

    public void push(int node) {
        stack1.push(node);
        stack2.push(stack2.isEmpty()?node:Math.min(stack2.peek(),node));
    }

    public void pop() {
        stack1.pop();
        stack2.pop();
    }

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

    public int min() {
        return stack2.peek();
    }
}