题解 | #包含min函数的栈#

import java.util.Stack;
public class Solution {
    Stack<Integer> stack = new Stack<>();
    int min = Integer.MAX_VALUE;
    public void push(int node) {
        stack.push(node);
        if (min > node) min = node;
    }
    public void pop() {
        int temp = stack.pop();
        if (temp == min) {
            int size = stack.size();
            min = Integer.MAX_VALUE;
            for (Integer integer : stack) min = min > integer ? integer : min;
        }
    }
    public int top() {
        return stack.peek();
    }
    public int min() {
        return min == Integer.MAX_VALUE ? 0 : min;
    }
    private void receiveStr(String str) {
        // 按照 , 分割
        String[] split = str.split(",");
        for (String s : split) {
            // 截取前三个字母
            String sub = s.substring(0, 3);
            String num = s.substring(3);
            switch (sub) {
                case "PSH":
                    this.push(Integer.parseInt(num));
                    break;
                case "TOP":
                    System.out.println(this.top());
                    break;
                case "MIN":
                    System.out.println(this.min());
                    break;
                case "POP":
                    this.pop();
                    break;
                default:
                    break;
            }
        }
    }
}