Little Ignorence may fail your code

Only one codition made my problem in topcoder’s 250 point pronlem in div 2 failed. You can view my code here http://www.topcoder.com/stat?c=problem_solution&rm=301792&rd=13898&pm=10489&cr=22692505. Can you tell what’s the value of s.size()-2 where s is the c++ string of value 1. Many of people will answer -1 to this but actually it will give some big interger with negative value. To get value of 1 we need to typecast s.size() to integer becouse s.size assumes its value to be unsigned integer. So while writing your code sometimes these things may lead to wrong answer.

In this srm 444, I challenged one guy successfully but mine code failed. So I learned two things from this one is “We dont see our faults but we see find fault in others” and other is “We should learn from our own mistakes”.