struct c++ programming?

Question

i have used class before, but i don't know struct, could I know how to solve the error?

Update:

the error is coming from the last part, i cannot return the value.

Answer 1

Favorite Answer

The error messages tell you exactly what you're doing wrong.  You defined a function that returns a Result struct, and the final line in that function does not return a Result struct.  It returns an integer.  Either change that return line to "return a;" or change the function definition to "int longestSubstring".  That's what the language requires.