IO format

http://www.cplusplus.com/reference/cstdio/scanf/?kw=scanf

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

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

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

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

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

http://www.cplusplus.com/reference/iolibrary/