Concerning data1, I assumed it is a string like data, but with different cities or records. However, as I didn't solved this kata yet, I can be wrong !
Concerning the definition of data in C, the '\0' is automatically added. For exemple, char string = "hello" ; creates a string of 6 char : "hello\0".

The problem description is not very clear. I have no idea of what data1 is in the description. And for the test case in C language, the char* data doesn't have a proper ending character, the program would have no idea of where the string should end.