Compilare: user.cpp: In function ‘void solve()’: user.cpp:67:64: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < V[el.x + dx[k]][el.y + dy[k]].size(); ++ i) ^ user.cpp: In function ‘void read()’: user.cpp:30:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("gheizere.in", "r", stdin); ^ user.cpp:31:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("gheizere.out", "w", stdout); ^ user.cpp:32:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &n, &m, &p); ^ user.cpp:33:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &v, &e); ^ user.cpp:36:52: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d %d", &x, &y, &r, &t, &d); ^