pmIcDg - Online Java Compiler & Debugging Tool

import java.util.*;

public class Main {

    static int find(int[] a, int key) {
        int left = 0, right = a.length - 1;

        while (left <= right) {
            int mid = (left + right) / 2;

            if (a[mid] == key) return mid;

            if (a[left] <= a[mid]) {
                if (key >= a[left] && key < a[mid]) {
                    right = mid - 1;
                } else {
                    left = mid + 1;
                }
            } else {
                if (key > a[mid] && key <= a[right]) {
                    left = mid + 1;
                } else {
                    right = mid - 1;
                }
            }
        }

        return -1;
    }

    public static void main(String[] args) {
        int[] arr = {11, 13, 18, 2, 3, 5, 7};
        int target = 3;

        int pos = find(arr, target);
        System.out.println(pos);
    }
}