Not Able to Clear all test Cases: String window

#1

I think the code is correct as i applied it on many custom inputs. Help!
https://hack.codingblocks.com/submission/1371250

#2

Your submission wont be available to me. Please copy the code to hackerblocks ide and post the link along with the problem link.

#3

Here it is:
https://ide.codingblocks.com/s/43759

#4

Your code is not producing correct results for many cases. Check them.
INPUT:
strings
ins
OUTPUT: tring
EXPECTED OUTPUT: ings

INPUT:
hackerblocks
rock
OUTPUT: ackerblo
EXPECTED OUTPUT: roblock

The question says substring of minimum length.