Compilare: user.cpp: In function ‘int similarity(const string&, const string&)’: user.cpp:29:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 1 ; i <= a.length() ; ++ i)for(j = 1 ; j <= b.length() ; ++ j){ ^ user.cpp:29:66: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 1 ; i <= a.length() ; ++ i)for(j = 1 ; j <= b.length() ; ++ j){ ^ user.cpp: In function ‘void BFS()’: user.cpp:41:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < G[nod].size() ; ++ i){ ^ user.cpp: In function ‘int main()’: user.cpp:71:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 1 ; i < H.size() ; ++ i) ^ user.cpp:82:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0 ; i < H.size() ; ++ i) ^