一、题目内容

二、题解

解法1：

思路

代码

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