Compilare: user.cpp: In function ‘int number(int&)’: user.cpp:25:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(Buffer,1,Bsize,stdin); ^ user.cpp:37:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(Buffer,1,Bsize,stdin); ^ user.cpp: In function ‘int main()’: user.cpp:48:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("distancesum.in","r",stdin); ^ user.cpp:49:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("distancesum.out","w",stdout); ^ user.cpp:50:32: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(Buffer,1,Bsize,stdin); p=0; ^ user.cpp: In function ‘int number(int&)’: user.cpp:42:5: warning: ‘c’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(ok) nr=nr*(-1); ^