Compilare: user.cpp: In function ‘int main()’: user.cpp:14:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<strlen(b);++i) ^ user.cpp:19:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(poz<=strlen(b)) ^ user.cpp:30:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i>=1 && poz<=strlen(b)) ^