Compilare: user.cpp: In function ‘void solve()’: user.cpp:36:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (l = 0; l < V[v[j]].size(); ++ l) ^ user.cpp: In function ‘void read()’: user.cpp:12:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("teroristi2.in", "r", stdin); ^ user.cpp:13:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &n, &k, &r); ^ user.cpp:16:31: 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 write()’: user.cpp:51:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("teroristi2.out", "w", stdout); ^