When compiling with Mingw 32bit, the size of long and unsigned long is 4 bytes, the size of long long and unsigned long long is 8 bytes.
- To print a long integer, the format of printf is “%ld”.
- To print an unsigned long integer, the printf format is “%lu”.
- To printf a long long integer, you should use “%lld” as the format of printf.
- To display an unsigned long long integer, the print format string you should use is “%llu”.
If you use “%lu” to display an unsigned long long integer, you may get “0” output, which is not you want.