Compilare: user.cpp: In function ‘int transform(int, int, std::string)’: user.cpp:40:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(s[0]==h[0] && s.size()>=l){ ^ user.cpp: In function ‘int main()’: user.cpp:85:26: warning: format ‘%s’ expects argument of type ‘char*’, but argument 3 has type ‘char (*)[20000]’ [-Wformat=] scanf("%d %s",&b,&c);//fin>>b>>s; ^