Poisonous Plants [Java]

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayDeque;

public class PoisonousPlants {
    public static void main(String[] args) throws IOException {
        BufferedReader input = new BufferedReader(new InputStreamReader(System.in));

        int n = Integer.parseInt(input.readLine());

        String[] plants = input.readLine().split(" ");

        ArrayDeque<Integer> indexes = new ArrayDeque<>();
        indexes.push(0);

        int[] daysCount = new int[n];

        for (int a = 0; a < n; a++) {
            int maxDays = 0;

            while (indexes.size() > 0 && Integer.parseInt(plants[indexes.peek()]) >= Integer.parseInt(plants[a])) {
                maxDays = Math.max(maxDays, daysCount[indexes.pop()]);
            }

            if (indexes.size() > 0) {
                daysCount[a] = maxDays + 1;
            }

            indexes.push(a);
        }

        System.out.println(maxCalc(daysCount));
    }

    private static int maxCalc(int[] days) {
        int max = Integer.MIN_VALUE;

        for (int currentDay : days) {
            if (currentDay > max) {
                max = currentDay;
            }
        }

        return max;
    }
}