Position of element in array of infinite numbers.java

public class InfiniteArray {
    public static void main(String[] args) {
        int[] arr = {2,5,9,15,18,25,29,37,42,47,49,59,67,79,89,90,93,95,99,107};
        int target = 29;
        System.out.println(ans(arr, target));
    }
    static int ans(int[] arr, int target) {
        int start = 0;
        int end = 1;
        while (target > arr[end]) {
            int temp = end + 1; 
            end = end + (end - start + 1) * 2;
            start = temp;
        }
        return binarySearch(arr, target, start, end);

    }
    static int binarySearch(int[] arr, int target, int start, int end) {
        while(start <= end) {
            int mid = start + (end - start) / 2;
            if (target < arr[mid]) {
                end = mid - 1;
            } else if (target > arr[mid]) {
                start = mid + 1;
            } else {
                return mid;
            }
        }
        return -1;
    }
}