Compilare: main.cpp: In function 'int main()': main.cpp:46:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(afis.size()!=n+1) ~~~~~~~~~~~^~~~~ main.cpp:51:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<afis.size()-1;++i) ~^~~~~~~~~~~~~~ main.cpp:27:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("domino.in","r",stdin); ^ main.cpp:28:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("domino.out","w",stdout); ^ main.cpp:30:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ main.cpp:33:38: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&v[i].x,&v[i].y); ^