Compilare: user.cpp: In function ‘int main()’: user.cpp:37:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<g[node].size()&&special[g[node][i]]==0;i++); ^ user.cpp:43:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<g[node].size();i++) ^ user.cpp:16:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("posta3.in","r",stdin); ^ user.cpp:17:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("posta3.out","w",stdout); ^ user.cpp:19:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&x); ^ user.cpp:21:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^ user.cpp:26:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&value[i]); ^