Compilare: user.cpp: In function ‘int main()’: user.cpp:33:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (sol.size()!=m) printf("-1"); else ^ user.cpp:15:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ksecv.in","r",stdin); ^ user.cpp:16:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ksecv.out","w",stdout); ^ user.cpp:18:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:20:55: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (int i=1;i<=n;i++) scanf("%d",&t[i]),sum+=t[i]; ^