Topic

Iterating over arrays

Problem

The longest ascending sequence

Write a program that reads an array of ints and outputs the length of the longest sequence in strictly ascending order. Elements of the sequence must go one after another. A single number is assumed to be an ordered sequence with the length = 1.

Input data format

The first line contains the size of an array. The second line contains elements of the array separated by spaces.

Example

The input array is 1 2 4 1 2 3 5 7 4 3. In this case, the length of the longest sequence in ascending order is 5. It includes the following elements: 1 2 3 5 7.

Solutions

My solution

import java.util.Scanner;

class Main {
    public static void main(String[] args) {
        
        Scanner scanner = new Scanner(System.in);
        int[] array = new int[scanner.nextInt()];
        int counter = 1;
        int maxLength = 1;

        for (int i = 0; i < array.length; i++) {
            array[i] = scanner.nextInt();
        }

        for (int i = 0; i < array.length; i++) {
            if (i + 1 < array.length) {
                if (array[i] < array[i + 1]) {
                    counter++;
                    if (maxLength < counter) {
                        maxLength = counter;
                    }
                } else {
                    counter = 1;
                }
            }
        }
        
        System.out.println(maxLength);
    }
}

Other solution

import java.util.Scanner; 

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

        int size = scanner.nextInt();
        int[] array = new int[size];

        for (int i = 0; i < size; i++) {
            array[i] = scanner.nextInt();
        }

        int max = 0;
        int count = 0;

        int before = array[0];

        for (int a : array) {
            if (before > a) {
                if (count > max) {
                    max = count;
                }
                count = 0;
            }

            before = a;
            count++;
        }

        if (count > max) {
            max = count;
        }

        System.out.println(max);
    }
}