Compilare: user.cpp: In function ‘void tarjan(int)’: user.cpp:27:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < L[x].size(); i ++) { ^ user.cpp: In function ‘int main()’: user.cpp:70:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < sol[i].size(); j ++) ^