Compilare: user.cpp: In function ‘int main()’: user.cpp:43:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("prefix2.in","r",stdin); ^ user.cpp:44:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("prefix2.out","w",stdout); ^ user.cpp:45:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",a); ^ user.cpp: In function ‘int verific(int)’: user.cpp:13:24: warning: array subscript is below array bounds [-Warray-bounds] q=(d[w+u-1]-d[w-1]*p[u])% mo; ^