What we're doing above is specifying two pointers, start and end. start points to the beginning of the string, and end is a pointer to the last character. Taking the example input racecar, as we run through it, these are the comparisons we'll see:
xxxxxxxxxxracecar^ ^racecar ^ ^racecar ^ ^racecar ^TrueOUTPUT
:001 > Cmd/Ctrl-Enter to run, Cmd/Ctrl-/ to comment
