I have a doubt in the question -'form the biggest no'

#1

I have written this code and all the sample inputs are giving correct output with this code. However, when I submit the code, none of the test cases are being passed. Pl help.

#2

Consider a case:
1
2
98 9

Expected O/p:
998

Your O/p:
989

The custom compare function must be something like this:
bool mycompare(string a,string b)
{
string ab=a+b;
string ba=b+a;
return ab>ba;
}

#3

Thank you for your help!