Compilare: main.cpp: In function 'void bfs(int)': main.cpp:20:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<g[u].size(); i++) ~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:36:37: 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:37:39: 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:39:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &t); ^ main.cpp:41:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:43:44: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &v[i].x, &v[i].y); ^ main.cpp:65:16: warning: 'ii' may be used uninitialized in this function [-Wmaybe-uninitialized] bfs(ii); ^