Compilare: main.cpp: In function 'int main()': main.cpp:26:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("amici2.in", "r", stdin); ^ main.cpp:27:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("amici2.out", "w", stdout); ^ main.cpp:28:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ main.cpp:30:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ main.cpp:34:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &u, &v); ^ main.cpp: In function 'int bfs(int)': main.cpp:22:14: warning: 'q' may be used uninitialized in this function [-Wmaybe-uninitialized] return dis[q]; ^