Compilare: user.cpp: In function ‘int main()’: user.cpp:70:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<bands.size()-1;i++) ^ user.cpp: In function ‘int i32()’: user.cpp:31:32: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,LEN,f); ^ user.cpp:40:32: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,LEN,f); ^ user.cpp:49:32: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,LEN,f); ^