Compilare: user.cpp: In function ‘char divide_et_impera(long long int, long long int, long long int, int)’: user.cpp:12:17: warning: unused variable ‘hz’ [-Wunused-variable] int hz = 0,ak = 0;; ^ user.cpp:12:24: warning: unused variable ‘ak’ [-Wunused-variable] int hz = 0,ak = 0;; ^ user.cpp:25:17: warning: unused variable ‘hz’ [-Wunused-variable] int hz = 0,ak = 0;; ^ user.cpp:25:24: warning: unused variable ‘ak’ [-Wunused-variable] int hz = 0,ak = 0;; ^ user.cpp: In function ‘int main()’: user.cpp:67:12: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses] in >> s+1; ^ user.cpp: In function ‘char divide_et_impera(long long int, long long int, long long int, int)’: user.cpp:63:1: warning: control reaches end of non-void function [-Wreturn-type] } ^