10. Poisonous Plants

package StacksAndQueues.Exercise;

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 reader = new BufferedReader(new InputStreamReader(System.in));
        int numberOfPlants = Integer.parseInt(reader.readLine());
        String[] pesticidePerPlant = reader.readLine().split("\\s+");

        int[] days = new int[numberOfPlants];
        ArrayDeque<Integer> indices = new ArrayDeque<>();
        indices.push(0);
        for (int i = 1; i < numberOfPlants; i++) {
            int maxDays = 0;
            while (!indices.isEmpty()) {
                if (Integer.parseInt(pesticidePerPlant[indices.peek()]) >= Integer.parseInt(pesticidePerPlant[i])) {
                    maxDays = Math.max(maxDays, days[indices.pop()]);
                } else {
                    days[i] = maxDays + 1;
                    break;
                }
            }
            indices.push(i);
        }

        System.out.println(getMax(days));
    }

    public static Integer getMax(int[] array) {
        int max = Integer.MIN_VALUE;
        for (int num : array) {
            if (num > max) {
                max = num;
            }
        }
        return max;
    }
}