Poisonous Plants

package StacksAndQueues1;

import java.util.Arrays;
import java.util.Scanner;
import java.util.Stack;

public class PoisonousPlants {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int number = Integer.parseInt(scanner.nextLine());

        int[] plants = Arrays
                .stream(scanner.nextLine().split(" "))
                .mapToInt(Integer::parseInt)
                .toArray();
        int[] days = new int[number];

        Stack<Integer> stack = new Stack<>();
        stack.push(0);

        int max = -1;
        for (int i = 1; i < plants.length; i++) {
            int allDays = 0;
            while (stack.size() > 0 && plants[stack.peek()] >= plants[i]) {
                allDays = Math.max(days[stack.pop()], allDays);
            }
            if (stack.size() > 0) {
                days[i] = allDays + 1;
                if (allDays + 1 > max) {
                    max = allDays + 1;
                }
            }
            stack.push(i);
        }
        System.out.println(max);
    }
}