Compilare: user.cpp: In function ‘void PerfectEliminationOrder()’: user.cpp:31:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<g[node].size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:56:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<g[order[i]].size();j++) ^ user.cpp:41:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tric.in","r",stdin); ^ user.cpp:42:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tric.out","w",stdout); ^ user.cpp:45:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:47:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^