Compilare: user.cpp: In function ‘int befeu()’: user.cpp:40:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < G[nod].size(); ++j) ^ user.cpp: In function ‘int main()’: user.cpp:87:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[sink].size(); ++i) ^ user.cpp: In function ‘int befeu()’: user.cpp:31:19: warning: iteration 210u invokes undefined behavior [-Waggressive-loop-optimizations] viz[i] = 0; ^ user.cpp:30:22: note: containing loop for(int i = 0; i <= 2 * maxn; ++i) ^