School, 09.09.2017, Ex6, max sequence length

public class Ex6 {
    // Write a Java program to find the length of the longest consecutive
    // elements sequence from a given unsorted array of integers.
    // Sample array: [49, 1, 3, 200, 2, 4, 70, 5]
    // The longest consecutive elements sequence is [1, 2, 3, 4, 5], therefore
    // the program will return its length 5.

    public static void main(String[] args) {
        int[] arr = { 49, 1, 3, 200, 2, 4, 70, 5 };

        int maxLength = 0;

        for (int i = 0; i < arr.length; i += 1) {
            int length = chainLength(arr, arr[i]);
            if (length > maxLength) {
                maxLength = length;
            }
        }

        System.out.println("Max chain length is " + maxLength);

    }

    // return true if n exists in array
    public static boolean isFound(int[] arr, int n) {
        for (int i = 0; i < arr.length; i += 1) {
            if (arr[i] == n)
                return true;
        }

        return false;
    }

    // length of chain starting from start
    public static int chainLength(int[] arr, int start) {
        int length = 0;

        while (isFound(arr, start)) {
            length += 1;
            start += 1;
        }

        return length;
    }

}