Compilare: user.cpp: In function ‘int main()’: user.cpp:49:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sume2.in","r",stdin); ^ user.cpp:50:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sume2.out","w",stdout); ^ user.cpp:51:22: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(f,1,MAX,stdin); ^ user.cpp: In function ‘long long int bs(int)’: user.cpp:29:20: warning: ‘mid’ may be used uninitialized in this function [-Wmaybe-uninitialized] int low=1,high=N,mid; ^