Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:29:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < a[x].size() ;++i) ^ user.cpp:34:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[nod].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:42:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("stramosi.in","r",stdin); ^ user.cpp:43:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("stramosi.out","w",stdout); ^ user.cpp:44:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:47:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^ user.cpp:57:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&q[i].x,&q[i].y); ^