HtDP Problem Set
An ft-node is one of:-
(make-child ft-node ft-node symbol number symbol)
Develop the function get-mothers. The function consumes an ft-node and produces a list of all mother's names present in the tree.
Hint: Use the Scheme operation
append, which consumes any number of lists and produces their concatenation.
Develop the function born-after. The function consumes an ft-node and a year and produces a list of names of family members who were born after that year.
A Web-page (short: WP) is one of:1. empty; 2. (cons symbol WP); or 3. (cons WP WP)
Develop the function remove-wp. The function consumes a Web-page and creates a new Web-page in which any pages that start with the special symbol '%remove are replaced with the empty Web-page.
A peer-to-peer network (like GNUtella) consists of individual nodes that are connected to the rest of the network through one or more neighboring nodes. In a simplified model, each node has only one neighbor and a list of files that it can serve. Every node has a unique number representing its address.
(define-struct file (name contents)) (define-struct node (address files neighbor))A P2P-Network is one of: -
(make-node number list-of-File P2P-Network)A list-of-file is one of - empty - (cons File list-of-file) A File is a structure:
(make-file symbol string)
Develop the function P2P-search. The function consumes the name of file and a P2P-network and returns the address of the first node that is discovered to have the file or false if the file does not exist anywhere within the network.
Optional: A copyright enforcement group wants to collect the addresses of all nodes on a P2P-Network that are hosting a particular file. Develop the function P2P-search-all, which is like P2P-search except that it returns the list of addresses of all nodes having a copy of the file being searched for.
See previous problem for data definitions.
Develop the function P2P-get. The function consumes the name of file, the address of a node, and a P2P-network and returns the contents of the file. Assume that both the node and file exist.
|Jamie Raymond||Matthias Felleisen|
01 december 2003