I want to learn discrete mathematics by reading book by myself but I find sometime it's very hard to understand what author trying to say.
I want to know, are there any good online video that teach discrete mathematic?
Check out the free audio/video courses in mathematics available through MIT OpenCourseWare: http://ocw.mit.edu/courses/audio-video-courses/#mathematics
It's an excellent course with video lectures and readings for someone just starting out to study university level discrete mathematics; especially in relation to computer science. Hope this helps.
This is an actual course in Discrete Mathematics, more specifically: Mathematics for Computer Science from the MIT OpenCourseWare -> Mathematics for Computer Science - 6.042J / 18.062J
Introduction to higher mathematics covers many topics from discrete math. http://www.youtube.com/playlist?list=PLZzHxk_TPOStgPtqRZ6KzmkUQBQ8TSWVX Discrete mathematical structures is harder to understand but is very comprehensive. http://www.youtube.com/playlist?list=PL0862D1A947252D20
Try Math Doctor Bob on Youtube. He talks a lot about discrete maths
Try this one. Full video lecture in discrete math. This course have recenlty taken in university of colorodo. Good luck---- - http://cmes.uccs.edu/Fall2012/Math215/archive.php