Find Minimum Reverse Operations

Question

Grayscale images at a company are saved as binary strings: a white pixel is written as '1' and a black pixel as '0'. Reading an image's string from the last character to the first gives the image's reverse. Making a backup relies on a single move, which may be used as often as needed: take any one character out of the string, wherever it sits, and put it back at the very end. ...