Compilare: user.cpp: In function ‘int main()’: user.cpp:48:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<A.size()-1; i++) ~^~~~~~~~~~~ user.cpp:50:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=i+1; j<A.size(); j++) ~^~~~~~~~~ user.cpp:64:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0; k<F[A[i]].size(); k++) ~^~~~~~~~~~~~~~~ user.cpp:70:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int l=0; l<F[A[j]].size(); l++) ~^~~~~~~~~~~~~~~