Compilare: user.cpp: In function ‘int main()’: user.cpp:53:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("politie.in", "r", stdin); ^ user.cpp:54:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("politie.out", "w", stdout); ^ user.cpp:58:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &N, &M, &D, &P); ^ user.cpp:69:87: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &edges[i].from, &edges[i].to, &edges[i].type, &edges[i].danger); ^