Compilare: user.cpp: In function ‘void read(int&)’: user.cpp:47:45: 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,buffersize,stdin); ll=0; ^ user.cpp:55:45: 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,buffersize,stdin); ll=0; ^ user.cpp: In function ‘int main()’: user.cpp:63:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cai.in","r",stdin); ^ user.cpp:64:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cai.out","w",stdout); ^ user.cpp:65:37: 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,buffersize,stdin); ll=0; ^