Compilare: main.cpp: In function 'void BFS(int, int)': main.cpp:29:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i < ad[k].size();++i){ ~~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:44:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("graf.in", "r", stdin); ^ main.cpp:45:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("graf.out", "w", stdout); ^ main.cpp:46:44: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &poz1, &poz2); ^ main.cpp:48:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^