Compilare: user.cpp: In function ‘int main()’: user.cpp:80:12: 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:76:1: warning: control reaches end of non-void function [-Wreturn-type] } ^