Why turbo C++ and sololearn gives different output ?

Question

https://code.sololearn.com/cMK2p0989IJS/?ref=app
The code mentioned above gives different outputs on Turbo c++ and Sololearn, why ?

Answer 1

Undefined behaviour.
There are many things which result in this. In your case it's multiple uses of increment operators in a single code sequence.

Take a look at other reasons and avoid them:
http://en.cppreference.com/w/cpp/language/ub