Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:22:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<sol[nod].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:42:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[a].size();i++){ ^ user.cpp:29:33: 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); ^ user.cpp:30:35: 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); ^ user.cpp:32:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&m,&x,&y); ^ user.cpp:34:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^