Compilare: user.cpp: In function ‘int main()’: user.cpp:21:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i <= s.length() ; ++i ) ^ user.cpp:25:16: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if ( s[i] != ')' && s[i] != '(' && s[i] != ',') ^ user.cpp:36:16: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if ( s[i] != ')' && s[i] != '(' && s[i] != ',') ^ user.cpp:50:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int v = 1; v < V.size(); ++v ) ^ user.cpp:72:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < V2.size(); ++i ) ^