Compilare: user.cpp: In function ‘int main()’: user.cpp:18:8: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] s[i]=NULL; ^ user.cpp:20:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<strlen(s);i++){ ^ user.cpp:28:13: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(s[i]==';'|| s[i]=='.') ^ user.cpp:6:19: warning: variable ‘st’ set but not used [-Wunused-but-set-variable] { char s[100000],st[100000]; ^