Compilare: main.cpp: In function 'int dfs(int, int)': main.cpp:10:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<a[x].size();i++){ ~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:28:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sediu.in","r",stdin); ^ main.cpp:29:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sediu.out","w",stdout); ^ main.cpp:30:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:32:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &e, &r); ^