Added doctest and more explanation about Dijkstra execution. (#1014)

* Added doctest and more explanation about Dijkstra execution.

* tests were not passing with python2 due to missing __init__.py file at number_theory folder

* Removed the dot at the beginning of the imported modules names because 'python3 -m doctest -v data_structures/hashing/*.py' and 'python3 -m doctest -v data_structures/stacks/*.py' were failing not finding hash_table.py and stack.py modules.

* Moved global code to main scope and added doctest for project euler problems 1 to 14.

* Added test case for negative input.

* Changed N variable to do not use end of line scape because in case there is a space after it the script will break making it much more error prone.

* Added problems description and doctests to the ones that were missing. Limited line length to 79 and executed python black over all scripts.

* Changed the way files are loaded to support pytest call.

* Added __init__.py to problems to make them modules and allow pytest execution.

* Added project_euler folder to test units execution

* Changed 'os.path.split(os.path.realpath(__file__))' to 'os.path.dirname()'

project_euler/problem_08/sol1.py

@@ -1,15 +1,72 @@
+# -*- coding: utf-8 -*-
+"""
+The four adjacent digits in the 1000-digit number that have the greatest
+product are 9 × 9 × 8 × 9 = 5832.
+
+73167176531330624919225119674426574742355349194934
+96983520312774506326239578318016984801869478851843
+85861560789112949495459501737958331952853208805511
+12540698747158523863050715693290963295227443043557
+66896648950445244523161731856403098711121722383113
+62229893423380308135336276614282806444486645238749
+30358907296290491560440772390713810515859307960866
+70172427121883998797908792274921901699720888093776
+65727333001053367881220235421809751254540594752243
+52584907711670556013604839586446706324415722155397
+53697817977846174064955149290862569321978468622482
+83972241375657056057490261407972968652414535100474
+82166370484403199890008895243450658541227588666881
+16427171479924442928230863465674813919123162824586
+17866458359124566529476545682848912883142607690042
+24219022671055626321111109370544217506941658960408
+07198403850962455444362981230987879927244284909188
+84580156166097919133875499200524063689912560717606
+05886116467109405077541002256983155200055935729725
+71636269561882670428252483600823257530420752963450
+
+Find the thirteen adjacent digits in the 1000-digit number that have the
+greatest product. What is the value of this product?
+"""
 import sys
-def main():
-    LargestProduct = -sys.maxsize-1
-    number=input().strip()
-    for i in range(len(number)-12):
-        product=1
+
+N = """73167176531330624919225119674426574742355349194934\
+96983520312774506326239578318016984801869478851843\
+85861560789112949495459501737958331952853208805511\
+12540698747158523863050715693290963295227443043557\
+66896648950445244523161731856403098711121722383113\
+62229893423380308135336276614282806444486645238749\
+30358907296290491560440772390713810515859307960866\
+70172427121883998797908792274921901699720888093776\
+65727333001053367881220235421809751254540594752243\
+52584907711670556013604839586446706324415722155397\
+53697817977846174064955149290862569321978468622482\
+83972241375657056057490261407972968652414535100474\
+82166370484403199890008895243450658541227588666881\
+16427171479924442928230863465674813919123162824586\
+17866458359124566529476545682848912883142607690042\
+24219022671055626321111109370544217506941658960408\
+07198403850962455444362981230987879927244284909188\
+84580156166097919133875499200524063689912560717606\
+05886116467109405077541002256983155200055935729725\
+71636269561882670428252483600823257530420752963450"""
+
+
+def solution(n):
+    """Find the thirteen adjacent digits in the 1000-digit number n that have
+    the greatest product and returns it.
+ 
+    >>> solution(N)
+    23514624000
+    """
+    LargestProduct = -sys.maxsize - 1
+    for i in range(len(n) - 12):
+        product = 1
         for j in range(13):
-            product *= int(number[i+j])
+            product *= int(n[i + j])
         if product > LargestProduct:
             LargestProduct = product
-    print(LargestProduct)
+    return LargestProduct
 
 
-if __name__ == '__main__':
-    main()
+if __name__ == "__main__":
+    print(solution(N))

project_euler/problem_08/sol2.py

@@ -1,8 +1,73 @@
+# -*- coding: utf-8 -*-
+"""
+The four adjacent digits in the 1000-digit number that have the greatest
+product are 9 × 9 × 8 × 9 = 5832.
+
+73167176531330624919225119674426574742355349194934
+96983520312774506326239578318016984801869478851843
+85861560789112949495459501737958331952853208805511
+12540698747158523863050715693290963295227443043557
+66896648950445244523161731856403098711121722383113
+62229893423380308135336276614282806444486645238749
+30358907296290491560440772390713810515859307960866
+70172427121883998797908792274921901699720888093776
+65727333001053367881220235421809751254540594752243
+52584907711670556013604839586446706324415722155397
+53697817977846174064955149290862569321978468622482
+83972241375657056057490261407972968652414535100474
+82166370484403199890008895243450658541227588666881
+16427171479924442928230863465674813919123162824586
+17866458359124566529476545682848912883142607690042
+24219022671055626321111109370544217506941658960408
+07198403850962455444362981230987879927244284909188
+84580156166097919133875499200524063689912560717606
+05886116467109405077541002256983155200055935729725
+71636269561882670428252483600823257530420752963450
+
+Find the thirteen adjacent digits in the 1000-digit number that have the
+greatest product. What is the value of this product?
+"""
+
 from functools import reduce
 
-def main():
-    number=input().strip()
-    print(max([reduce(lambda x,y: int(x)*int(y),number[i:i+13]) for i in range(len(number)-12)]))
-    
-if __name__ == '__main__':
-    main()
+N = (
+    "73167176531330624919225119674426574742355349194934"
+    "96983520312774506326239578318016984801869478851843"
+    "85861560789112949495459501737958331952853208805511"
+    "12540698747158523863050715693290963295227443043557"
+    "66896648950445244523161731856403098711121722383113"
+    "62229893423380308135336276614282806444486645238749"
+    "30358907296290491560440772390713810515859307960866"
+    "70172427121883998797908792274921901699720888093776"
+    "65727333001053367881220235421809751254540594752243"
+    "52584907711670556013604839586446706324415722155397"
+    "53697817977846174064955149290862569321978468622482"
+    "83972241375657056057490261407972968652414535100474"
+    "82166370484403199890008895243450658541227588666881"
+    "16427171479924442928230863465674813919123162824586"
+    "17866458359124566529476545682848912883142607690042"
+    "24219022671055626321111109370544217506941658960408"
+    "07198403850962455444362981230987879927244284909188"
+    "84580156166097919133875499200524063689912560717606"
+    "05886116467109405077541002256983155200055935729725"
+    "71636269561882670428252483600823257530420752963450"
+)
+
+
+def solution(n):
+    """Find the thirteen adjacent digits in the 1000-digit number n that have
+    the greatest product and returns it.
+ 
+    >>> solution(N)
+    23514624000
+    """
+    return max(
+        [
+            reduce(lambda x, y: int(x) * int(y), n[i : i + 13])
+            for i in range(len(n) - 12)
+        ]
+    )
+
+
+if __name__ == "__main__":
+    print(solution(str(N)))