题解 | #包含min函数的栈#

import java.util.Stack;

public class Solution {

    Stack <Integer> normal = new Stack<Integer>();
    Stack <Integer> min = new Stack<Integer>();
  
    public void push(int node) {
        normal.push(node);
        if(min.isEmpty()==true){
            min.push(node);
        }else {
            if (node<min.peek()){
                min.push(node);
            }else{
                min.push(min.peek());
            }
        }
    }
    
    public void pop() {
        int now = normal.pop();
        min.pop();
    }
    
    public int top() {
        return normal.peek();
    }
    
    public int min() {
        return min.peek();
    }
}