Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:15:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0;k<g[nod].size();++k) ^ user.cpp: In function ‘void dfs_t(int)’: user.cpp:26:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0;k<t[nod].size();++k) ^ user.cpp: In function ‘int main()’: user.cpp:60:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v[i].size();++j) ^ user.cpp:31:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("retele.in","r",stdin);freopen("retele.out","w",stdout); ^ user.cpp:31:68: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("retele.in","r",stdin);freopen("retele.out","w",stdout); ^ user.cpp:33:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:37:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^