Compilare: main.cpp: In function 'void dfs(int, int)': main.cpp:20:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<tree[nod].size();i++) ~^~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:46:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("lca.in","r",stdin); ^ main.cpp:47:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("lca.out","w",stdout); ^ main.cpp:49:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%i %i",&n,&m); ^ main.cpp:53:23: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%i",&a); ^ main.cpp:71:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%i %i",&a,&b); ^