161. One Edit Distance

[ErdemT09]

Resolves: #86

Algorithm:

Firstly, we can do a simple optimization here. If the strings is (1 character) longer than the target, then remove some character from the strings is equivalent to adding a character to the target. In order to only consider adding and replacing, we can call the function again with reversed parameter order if that is the case.

With the operation above, assuming that the target is always longer the string, If target is more than a single character longer than the strings, that means that we cannot get to it in "one edit distance".

Then we iterate through the characters of the string. If 2 characters at the same indices of the string and the target aren't same, that means that this character is either a replacement from the original string, if both string lengths are the same, or a char is added to here in the target.

If the first one is the case, the rest of the two strings have to be same.
If the second one is the case, the rest of the string and the rest of the target starting 1 index after the current position (because of the inserted character) have to be the same. We return those 2 substring checks.

Since the length of the string is shorter than that of the target, we might have gone through all the characters of the string and might not have found any additions, which could be add the end of the target. If so, we can safely return true if the target is longer.

[altay9]

Es ist eine sehr schöne Erklärung.
Der Code ist ziemlich klar und unkompliziert.
Danke für die tolle Zusammenarbeit.