题解 | #包含min函数的栈#

用一个栈存储，元素，最小值，元素，最小值。。。。这样存储

import java.util.Stack;

public class Solution {

    Stack<Integer> we = new Stack<Integer>();
    int i;
    public void push(int node) {
        if(we.isEmpty()){
            i = node;
            we.push(i);
            we.push(node);
            
        }
        else{
            if(i > node){
                i = node;
            }
            we.push(i);
            we.push(node);
            
        }
    }
    
    public void pop() {
        we.pop();
        we.pop();
        int op = we.pop();
        int io = we.pop();
        we.push(io);
        we.push(op);
        i = io;
    }
    
    public int top() {
        return we.peek();
    }
    
    public int min() {
        int op = we.pop();
        int io = we.pop();
        we.push(io);
        we.push(op);
        
        return io;
    }
}