%ld?

Answer 1

%ld is a format specifier for long int.
When an integer is too long , a long int format specifier is used.😀

Answer 2

Be more descriptive when asking a question.

Reference helps
http://www.cplusplus.com/reference/cstdio/scanf/

http://www.cplusplus.com/reference/cstdio/printf/

Follow this guide on posting a question 👍

https://www.sololearn.com/Discuss/333866/?ref=app

Answer 3

It means "Long integer".
For instance, if integer is 2 bytes, long integer is 4 bytes. It allows to you to use longer values