Every binary search in part one had a sorted array underneath it. Take that away and most people assume the technique goes with it. It does not — sortedness was never the requirement, only the most convenient way to meet it. This is the second of three posts on Joseph Choi’s binary search session deck. Seven problems here, in two families: three where the array rises and then falls, and four where a sorted array has been rotated. In both, something other than the sort order tells you which half to keep. As in part one, every listing was compiled READ MORE