Compilare: user.cpp:29:25: warning: multi-character character constant [-Wmultichar] while(s[i]!='-1') ^ user.cpp: In function ‘int main()’: user.cpp:22:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<=s.size();i++) ^ user.cpp:61:28: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(s[i-1]==' ' and (s[i-2]==')' || s[i-2]==' ')|| s[i-1]==')') ^