Compilare: user.cpp: In function ‘void Read()’: user.cpp:16:7: warning: unused variable ‘i’ [-Wunused-variable] int i; ^ user.cpp: In function ‘void Solve()’: user.cpp:34:8: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(s[i]==')') ^ user.cpp:29:8: warning: unused variable ‘x’ [-Wunused-variable] char x; ^