Compilare: user.cpp: In function ‘int longest()’: user.cpp:12:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<strlen(s);i++){ ^ user.cpp:18:52: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(pi[pos+len-1]>=best && pos+len-1<strlen(s)){ ^ user.cpp: In function ‘int main()’: user.cpp:30:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<strlen(s);i++){ ^