Programming challenge: the position of the element

PositionOfTheElement.java

// Programming challenge: the position of the element
// Original post: https://blog.svpino.com/2015/05/24/programming-challenge-the-position-of-the-element
public class Main {

	private static int[] array = { 1, 3, 5, 6 };

	// Solution using a sequential search - O(n)
	private static int sequential(int target) {
		if (target < array[0]) {
			return 0;
		}

		if (target > array[array.length - 1]) {
			return array.length;
		}

		for (int i = 0; i < array.length; i++) {
			if (array[i] >= target) {
				return i;
			}
		}

		return 0;
	}

	// Solution using a binary search - O(log n)
	private static int binary(int target) {
		int left = 0;
		int right = array.length - 1;
		while (left <= right) {
			int mid = left + (right - left) / 2;
			if (target < array[mid]) {
				right = mid - 1;
			}
			else if (target > array[mid]) {
				left = mid + 1;
			}
			else {
				return mid;
			}
		}
		
		return left;
	}

	public static void main(String[] args) {
		String format = "* Target %d should return %d [%s]";
		System.out.println("Using a sequential search solution:");
		System.out.println(String.format(format, 0, 0, sequential(0) == 0));
		System.out.println(String.format(format, 1, 0, sequential(1) == 0));
		System.out.println(String.format(format, 2, 1, sequential(2) == 1));
		System.out.println(String.format(format, 3, 1, sequential(3) == 1));
		System.out.println(String.format(format, 4, 2, sequential(4) == 2));
		System.out.println(String.format(format, 5, 2, sequential(5) == 2));
		System.out.println(String.format(format, 6, 3, sequential(6) == 3));
		System.out.println(String.format(format, 7, 4, sequential(7) == 4));
		
		System.out.println("\r\nUsing a binary search solution:");
		System.out.println(String.format(format, 0, 0, binary(0) == 0));
		System.out.println(String.format(format, 1, 0, binary(1) == 0));
		System.out.println(String.format(format, 2, 1, binary(2) == 1));
		System.out.println(String.format(format, 3, 1, binary(3) == 1));
		System.out.println(String.format(format, 4, 2, binary(4) == 2));
		System.out.println(String.format(format, 5, 2, binary(5) == 2));
		System.out.println(String.format(format, 6, 3, binary(6) == 3));
		System.out.println(String.format(format, 7, 4, binary(7) == 4));
	}
}