Compilare: user.cpp: In function ‘int main()’: user.cpp:14:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size();i++) ^ user.cpp:20:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(st<=dr && dr<s.size()) ^ user.cpp:9:12: warning: unused variable ‘j’ [-Wunused-variable] int n,i,j,k; ^ user.cpp:54:4: warning: ‘lj’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(i=li;i<=lj;i++) ^ user.cpp:55:14: warning: ‘li’ may be used uninitialized in this function [-Wmaybe-uninitialized] cout<<s[i]; ^