Jeff Moss (hacker) Jeff Moss (hacker) Jeff Moss, also known as Dark Tangent, (born January 1, 1975) is an American hacker, computer and internet security expert who founded the Black Hat and DEF CON computer security conferences. Jeff received his first computer at the age of 10. He became fascinated because he wasn't old enough to drive a car or vote, but he could engage in adult conversation with people all over the country. Moss graduated from Gonzaga University with a BA in Criminal Justice. He worked for Ernst & Young, LLP in their Information System Security division and was a director at
Prefix sum runs in linear time for integer keys that are smaller than the number of items, and is frequently used as part of radix sort, a fast algorithm for sorting integers that are less restricted in magnitude. List ranking, the problem of transforming a linked list into an array that represents the same sequence of items, can be viewed as computing a prefix sum on the sequence 1, 1, 1, ... and then mapping each item to the array position given by its prefix sum value; by combining list ranking, prefix sums, and Euler tours, many important problems on trees may