The issue was to find the longest common substring.
What this means is: Given the word "abracadabra" you are looking for the longest repeated set of characters.
The longest repeated sub-string is "abra" which appears at positions 0 and 7 (counting from 0).
The solution the person presented involved putting the strings from smallest to largest into a dictionary (hash table) with counts of iterations.
a-4
b-2
ab-2
And then walking the tree to find the largest result. This solution seems odd to me.
My solution is to make a dynamic array that can be queried for contents. Further, doing it from longest to shortest:
Edit
gwenix points out a string can't be repeated until it's no more than half the length. So start from longest string (len /2) rounded down.End Edit
Solution:
Get longest string: abracadabra
Is string in array? YES? got answer and bail; No --> add to array
*Reduce look string by 1 character
Move to start of target string:
**Get look string: abracadabr
Is string in array? YES? got answer and bail; No --> add to array
Is look string at end of target string? Yes --> loop back to *; No --> move forward one character and loop back to **
This is massively not optimised for time or processing. But it's a first stab.
Also, just pseudo code... loop counters would be my next pass.
Comments? Improvements?
