Compilare: user.cpp: In function ‘void DFS(int, int)’: user.cpp:23:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<v[k].size(); ++i) ^ user.cpp: In function ‘void DFS2(int)’: user.cpp:31:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<v[k].size(); ++i) ^ user.cpp: In function ‘void sortaret()’: user.cpp:42:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<v[k].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:76:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j=0; j<v[i].size(); ++j) ^