8. Project Euler #8 : Largest product in a series.
Difficulty level is 5%. This is a good problem that can be used at searching substring in a document. In order to search a sub-string from a document, hashing can be used. At this problem, product is needed, but, It is needed to check overflow and zero multiply. 13's single digit product can make 9's power 13, 2,541,865,828,329. 32bit integer can express about 4 billion, so I used 64bit integer ..
2015. 4. 16.