/**
 *
 * Ashish Patel
 * e: ashishsushilPatel@gmail.com
 * w: https://ashish.me
 *
 */

class IndexOfFirstOccurrenceInSorted {

  static int func(int[] nums, int target) {
    int start = 0;
    int end = nums.length - 1;
    while (start <= end) {
      int mid = Math.abs((start + end) / 2);
      if (nums[mid] > target) {
        end = mid - 1;
      } else if (nums[mid] < target) {
        start = mid + 1;
      } else {
        if (mid == 0 || nums[mid - 1] != nums[mid]) {
          return mid;
        } else {
          end = mid - 1;
        }
      }
    }
    return -1;
  }

  public static void main(String[] args) {
    int[] nums = new int[] { 1, 4, 8, 23, 67, 123, 123, 123, 3466, 5687 };
    int result = func(nums, 123);
    System.out.println(result);
  }
}