This exactly. The author is not describing their approach very well, so I stopped reading because it was frustrating to try to figure out if they tried this sol

This exactly. The author is not describing their approach very well, so I stopped reading because it was frustrating to try to figure out if they tried this solution. The simple statement of the approach is: Use binary search, but instead of using the middle as the pivot, use the estimated position heuristic as the pivot for each iteration.