Compilare: user.cpp: In function ‘void solve()’: user.cpp:33:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < V[i].size(); ++ j) ^ user.cpp: In function ‘void read_edge()’: user.cpp:12:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^ user.cpp: In function ‘void read()’: user.cpp:19:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("steinsgate.in", "r", stdin); ^ user.cpp:20:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &n, &m, &k); ^ user.cpp:23:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &risk[i]); ^ user.cpp: In function ‘void write()’: user.cpp:39:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("steinsgate.out", "w", stdout); ^