Unique character code not working when ran in linux but fine in windows (C++)

Question

When I run the code in windows, it works as expected. But when I run it in linux, the program doesn't run as expected and produces a completely different output.

I'm assuming its a problem in the all_unique_letters method, but I can't seem to figure it out.

Answer 1

In bool all_unique_letters(const string &s) , unsigned int v; is used without being initialized. If it contains something else that 0 , the function reports a letter as a duplicate when it is not.