Compilare: user.cpp: In function ‘int main()’: user.cpp:89:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(b==sol[x].size()) a=1; ^ user.cpp:40:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divisorgraph.in", "r", stdin); ^ user.cpp:41:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("divisorgraph.out", "w", stdout); ^ user.cpp:49:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(scanf("%d",&t);t;t--) ^ user.cpp:51:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:59:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^