Compilare: user.cpp: In function ‘void Solve()’: user.cpp:49:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < M[vf].size(); ++i) ^ user.cpp: In function ‘void Read()’: user.cpp:24:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:27:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y, &cost); ^