Compilare: user.cpp: In function ‘int main()’: user.cpp:89:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<(sol.size()-1);i++) ^ user.cpp:107:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<(sol.size()-1);i++) ^ user.cpp:19:35: 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); ^ user.cpp:20:37: 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); ^ user.cpp:21:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:24:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^