Security hacker laws against computer hacking. Neal Patrick testified before the U.S. House of Representatives on September 26, 1983, about the dangers of computer hacking, and six bills concerning computer crime were introduced in the House that year. As a result of these laws against computer criminality, white hat, grey hat and black hat hackers try to distinguish themselves from each other, depending on the legality of their activities. These moral conflicts are expressed in The Mentor's "The Hacker Manifesto", published 1986 in "Phrack". Use of the term hacker meaning computer criminal was also advanced by the title "Stalking the Wily Hacker",
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