how to sort?

[Anakin]

EssGeEich, Thank for your reply, I changed my code with your suggestion , output file is sorted but all are in integer format.i.g

[S G H]

No wonder since you use strtoUL and stoI. ( unsigned long and int, respectively).
You don't read floats, you will not print floats.

[Anakin]

I didn't get actually, read and write file was given by my teacher. could you say what part ,should I change?

[Anakin]

by searching I found my problem and fixed it , thank you all for your help.
thank you.