First coding challenges

Author: seba3c

README.md

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+# Python Coding Challenges
+Compilation of coding challenges implemented in Python 3.6 programming language.
+
+These are my solutions for coding challenges extracted from different sources, including:
+
+* [Hacker Rank](https://www.hackerrank.com)
+
+Most of the coding challenges solved, have a link to the original statement problem.

src/__init__.py

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+# -*- coding: utf-8 -*-
+'''
+Given a flat file of book metadata, write a Library class that parses the book data and provides an API that lets you search for all books containing a word.
+
+API:
+
+Library
+- <constructor>(input) -> returns a Library object
+- search(word) -> returns all books that contain the word anywhere in the
+                  title, author, or description fields. Only matches *whole* words.
+E.g. Searching for "My" or "book" would match a book containing "My book", but searching for "My b" or "boo" would *not* match.
+'''
+import re
+
+
+LIBRARY_DATA = """
+TITLE: Hitchhiker's Guide to the Galaxy
+AUTHOR: Douglas Adams
+DESCRIPTION: Seconds before the Earth is demolished to make way for a galactic freeway,
+Arthur Dent is plucked off the planet by his friend Ford Prefect, a researcher for the
+revised edition of The Hitchhiker's Guide to the Galaxy who, for the last fifteen years,
+has been posing as an out-of-work actor.
+
+TITLE: Dune
+AUTHOR: Frank Herbert
+DESCRIPTION: The troubles begin when stewardship of Arrakis is transferred by the
+Emperor from the Harkonnen Noble House to House Atreides. The Harkonnens don't want to
+give up their privilege, though, and through sabotage and treachery they cast young
+Duke Paul Atreides out into the planet's harsh environment to die. There he falls in
+with the Fremen, a tribe of desert dwellers who become the basis of the army with which
+he will reclaim what's rightfully his. Paul Atreides, though, is far more than just a
+usurped duke. He might be the end product of a very long-term genetic experiment
+designed to breed a super human; he might be a messiah. His struggle is at the center
+of a nexus of powerful people and events, and the repercussions will be felt throughout
+the Imperium.
+
+TITLE: A Song Of Ice And Fire Series
+AUTHOR: George R.R. Martin
+DESCRIPTION: As the Seven Kingdoms face a generation-long winter, the noble Stark family
+confronts the poisonous plots of the rival Lannisters, the emergence of the
+White Walkers, the arrival of barbarian hordes, and other threats.
+
+"""
+
+
+def remove_non_alpha_chars(s):
+    s = s.replace("\n", " ")
+    s = re.sub("[^a-zA-Z0-9\s']+", "", s)
+    return s.strip()
+
+
+class Book:
+    def __init__(self, title, author, desc):
+        self.title = remove_non_alpha_chars(title)
+        self.author = remove_non_alpha_chars(author)
+        self.description = remove_non_alpha_chars(desc)
+
+        words = set(self.title.split(" "))
+        words = words.union(set(self.author.split(" ")))
+        words = words.union(set(self.description.split(" ")))
+        self.words = words
+
+
+class Library:
+
+    def __init__(self, data):
+
+        book_text = data.split("\n\n")
+        self.books = []
+        for t in book_text:
+            if not t:
+                continue
+
+            m = re.search('.*TITLE:(.*)AUTHOR:(.*)DESCRIPTION:(.*)', t, re.DOTALL)
+
+            title = m.group(1)
+            author = m.group(2)
+            description = m.group(3)
+            self.books.append(Book(title, author, description))
+
+    def search(self, word):
+        results = []
+        for b in self.books:
+            if word in b.words:
+                results.append(b)
+        return results
+
+
+library = Library(LIBRARY_DATA)
+first_results = library.search("Arrakis")
+assert first_results[0].title == "Dune"
+second_results = library.search("winter")
+assert second_results[0].title == "A Song Of Ice And Fire Series"
+third_results = library.search("demolished")
+assert third_results[0].title == "Hitchhiker's Guide to the Galaxy"
+fourth_results = library.search("the")
+assert len(fourth_results) == 3
+assert fourth_results[1].title == "Dune"
+assert fourth_results[2].title == "A Song Of Ice And Fire Series"
+assert fourth_results[0].title == "Hitchhiker's Guide to the Galaxy"
+print("All tests passed!")

src/adr_books.py

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+# -*- coding: utf-8 -*-
+
+"""
+Given a string checks if it is balanced in relation to (){}[] symbols.
+"""
+
+
+def is_match(ss):
+    symbol_stack = []
+    for c in ss:
+        if c in ['(', "[", "{"]:
+            symbol_stack.insert(0, c)
+        elif c in [')', "]", "}"]:
+            if not symbol_stack:
+                return False
+            else:
+                e = symbol_stack.pop(0)
+                mismatch = (c == ')' and e != '(') or (c == ']' and e != '[') or (c == '}' and e != '{')
+                if mismatch:
+                    return False
+    return len(symbol_stack) == 0
+
+
+assert is_match("[[a]]")
+assert not is_match("[[a]")
+assert is_match("{aasd{a}dasdasd}")
+assert is_match("")
+assert is_match("a23131a")
+assert is_match("(a)2{31}31a [[]]")
+assert is_match("{{{[[((([])))]]}}}")
+assert not is_match("{{{[[(((()))]]}}}")
+assert not is_match("(a)2{31}31a [[)]")
+print("All test passed!")

src/adr_match.py

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+# -*- coding: utf-8 -*-
+
+
+def has_same_elements(s1, s2):
+    s1_dict = {}
+    s2_dict = {}
+    for s in s1:
+        s1_dict[s] = s1_dict.get(s, 0) + 1
+    for s in s2:
+        s2_dict[s] = s2_dict.get(s, 0) + 1
+    return s1_dict == s2_dict
+
+
+def anagrams(word=None):
+
+    if (not word):
+        return []
+
+    anagram_list = []
+
+    with open("wl.txt") as f:
+        words = f.readlines()
+    words = list(map(lambda x: x.replace("\n", ""), words))
+
+    for w in words:
+        if has_same_elements(word, w):
+            anagram_list.append(w)
+
+    return anagram_list
+
+
+if __name__ == '__main__':
+    print(anagrams())
+    print(anagrams("horse"))