Is number of variables affect the quality of our code?

Answer 1

If you place your variables properly, within the scopes where they are used it will do you least harm, and don't forget there are arrays and containers, which take more memory than those of the basic types, an array of int with 10 elements takes as much as ten int variable : )

Hth, cmiiw

Answer 2

Yes definitely, memory management is the first case you have to lookup for.