二分查找边缘

 public int firstEqualGreater(int[] nums, int target) {
        int low = 0;
        int high = nums.length;

        while (low < high) {
            int mid = low + (high - low) / 2;
            if (nums[mid] < target)
                low = mid + 1;
            else
                high = mid;
        }
        return low;
    }