Fix flake8 issues (#837)

Author: ankit167

algorithms/compression/elias.py

@@ -1,17 +1,20 @@
 """
-Elias γ code or Elias gamma code is a universal code encoding positive integers.
-It is used most commonly when coding integers whose upper-bound cannot be determined beforehand.
-Elias δ code or Elias delta code is a universal code encoding the positive integers,
+Elias γ code or Elias gamma code is a universal code
+encoding positive integers.
+It is used most commonly when coding integers whose
+upper-bound cannot be determined beforehand.
+Elias δ code or Elias delta code is a universal code
+ encoding the positive integers,
 that includes Elias γ code when calculating.
 Both were developed by Peter Elias.
 
 """
-from math import log,ceil
+from math import log
 
-log2 = lambda x: log(x,2)
+log2 = lambda x: log(x, 2)
 
 # Calculates the binary number
-def binary(x,l=1):
+def binary(x, l=1):
 	fmt = '{0:0%db}' % l
 	return fmt.format(x)
 
@@ -21,20 +24,21 @@ def unary(x):
 
 def elias_generic(lencoding, x):
 	"""
-	The compressed data is calculated in two parts. 
-	The first part is the unary number of 1 + ⌊log2(x)⌋. 
+	The compressed data is calculated in two parts.
+	The first part is the unary number of 1 + ⌊log2(x)⌋.
 	The second part is the binary number of x - 2^(⌊log2(x)⌋).
 	For the final result we add these two parts.
 	"""
-	if x == 0: return '0'
+	if x == 0:
+		return '0'
 
 	first_part = 1 + int(log2(x))
 
 	a = x - 2**(int(log2(x)))
 
 	k = int(log2(x))
 
-	return lencoding(first_part) + binary(a,k)
+	return lencoding(first_part) + binary(a, k)
 
 def elias_gamma(x):
 	"""
@@ -46,4 +50,4 @@ def elias_delta(x):
 	"""
 	For the first part we put the elias_g of the number.
 	"""
-	return elias_generic(elias_gamma,x)
+	return elias_generic(elias_gamma, x)

algorithms/dp/coin_change.py

@@ -1,28 +1,31 @@
 """
 Problem
-Given a value n, if we want to make change for N cents, and we have infinite supply of each of 
-coins = {S1, S2, .. , Sm} valued coins, how many ways can we make the change? 
+Given a value n, if we want to make change for N cents,
+and we have infinite supply of each of
+coins = {S1, S2, .. , Sm} valued coins, how many ways
+can we make the change?
 The order of coins doesn't matter.
-For example, for n = 4 and coins = [1, 2, 3], there are four solutions: 
-[1, 1, 1, 1], [1, 1, 2], [2, 2], [1, 3]. 
-So output should be 4. 
+For example, for n = 4 and coins = [1, 2, 3], there are
+four solutions:
+[1, 1, 1, 1], [1, 1, 2], [2, 2], [1, 3].
+So output should be 4.
 
-For n = 10 and coins = [2, 5, 3, 6], there are five solutions: 
-[2, 2, 2, 2, 2], [2, 2, 3, 3], [2, 2, 6], [2, 3, 5] and [5, 5]. 
+For n = 10 and coins = [2, 5, 3, 6], there are five solutions:
+[2, 2, 2, 2, 2], [2, 2, 3, 3], [2, 2, 6], [2, 3, 5] and [5, 5].
 So the output should be 5.
 
 Time complexity: O(n * m) where n is the value and m is the number of coins
 Space complexity: O(n)
 """
 
+
 def count(coins, n):
     # initialize dp array and set base case as 1
     dp = [1] + [0] * n
- 
+
     # fill dp in a bottom up manner
     for coin in coins:
         for i in range(coin, n+1):
             dp[i] += dp[i-coin]
 
     return dp[n]
-

algorithms/dp/edit_distance.py

@@ -1,34 +1,43 @@
-"""The edit distance between two words is the minimum number of letter insertions,
-letter deletions, and letter substitutions required to transform one word into another.
+"""The edit distance between two words is the minimum number
+of letter insertions, letter deletions, and letter substitutions
+required to transform one word into another.
 
-For example, the edit distance between FOOD and MONEY is at most four:
+For example, the edit distance between FOOD and MONEY is at
+most four:
 
 FOOD -> MOOD -> MOND -> MONED -> MONEY
 
-Given two words A and B, find the minimum number of operations required to transform one string into the other.
+Given two words A and B, find the minimum number of operations
+required to transform one string into the other.
 In other words, find the edit distance between A and B.
 
 Thought process:
 
-Let edit(i, j) denote the edit distance between the prefixes A[1..i] and B[1..j].
+Let edit(i, j) denote the edit distance between
+the prefixes A[1..i] and B[1..j].
 
 Then, the function satifies the following recurrence:
 
 edit(i, j) = i if j = 0
              j if i = 0
-             min(edit(i-1, j) + 1, 
+             min(edit(i-1, j) + 1,
                  edit(i, j-1), + 1,
                  edit(i-1, j-1) + cost) otherwise
 
-There are two base cases, both of which occur when one string is empty and the other is not.
-1. To convert an empty string A into a string B of length n, perform n insertions.
-2. To convert a string A of length m into an empty string B, perform m deletions.
+There are two base cases, both of which occur when one string is empty
+and the other is not.
+1. To convert an empty string A into a string B of length n,
+perform n insertions.
+2. To convert a string A of length m into an empty string B,
+perform m deletions.
 
 Here, the cost is 1 if a substitution is required,
-or 0 if both chars in words A and B are the same at indexes i and j, respectively.
+or 0 if both chars in words A and B are the same at
+indexes i and j, respectively.
 
 To find the edit distance between two words A and B,
-we need to find edit(m, n), where m is the length of A and n is the length of B.
+we need to find edit(m, n), where m is the length of A and n
+is the length of B.
 """
 
 

algorithms/dp/egg_drop.py

@@ -1,21 +1,21 @@
 """
-You are given K eggs, and you have access to a building with N floors 
-from 1 to N. Each egg is identical in function, and if an egg breaks, 
-you cannot drop it again. You know that there exists a floor F with 
-0 <= F <= N such that any egg dropped at a floor higher than F will 
-break, and any egg dropped at or below floor F will not break. 
-Each move, you may take an egg (if you have an unbroken one) and drop 
-it from any floor X (with 1 <= X <= N). Your goal is to know with 
-certainty what the value of F is. What is the minimum number of moves 
-that you need to know with certainty what F is, regardless of the 
+You are given K eggs, and you have access to a building with N floors
+from 1 to N. Each egg is identical in function, and if an egg breaks,
+you cannot drop it again. You know that there exists a floor F with
+0 <= F <= N such that any egg dropped at a floor higher than F will
+break, and any egg dropped at or below floor F will not break.
+Each move, you may take an egg (if you have an unbroken one) and drop
+it from any floor X (with 1 <= X <= N). Your goal is to know with
+certainty what the value of F is. What is the minimum number of moves
+that you need to know with certainty what F is, regardless of the
 initial value of F?
 
 Example:
 Input: K = 1, N = 2
 Output: 2
-Explanation: 
+Explanation:
 Drop the egg from floor 1.  If it breaks, we know with certainty that F = 0.
-Otherwise, drop the egg from floor 2.  If it breaks, we know with 
+Otherwise, drop the egg from floor 2.  If it breaks, we know with
 certainty that F = 1.
 If it didn't break, then we know with certainty F = 2.
 Hence, we needed 2 moves in the worst case to know what F is with certainty.
@@ -24,20 +24,21 @@
 # A Dynamic Programming based Python Program for the Egg Dropping Puzzle
 INT_MAX = 32767
 
+
 def egg_drop(n, k):
     # A 2D table where entery eggFloor[i][j] will represent minimum
     # number of trials needed for i eggs and j floors.
-    egg_floor = [[0 for x in range(k+1)] for x in range(n+1)]
- 
+    egg_floor = [[0 for x in range(k+1)] for x in range(n + 1)]
+
     # We need one trial for one floor and 0 trials for 0 floors
     for i in range(1, n+1):
         egg_floor[i][1] = 1
         egg_floor[i][0] = 0
- 
+
     # We always need j trials for one egg and j floors.
     for j in range(1, k+1):
         egg_floor[1][j] = j
- 
+
     # Fill rest of the entries in table using optimal substructure
     # property
     for i in range(2, n+1):
@@ -47,6 +48,6 @@ def egg_drop(n, k):
                 res = 1 + max(egg_floor[i-1][x-1], egg_floor[i][j-x])
                 if res < egg_floor[i][j]:
                     egg_floor[i][j] = res
- 
+
     # eggFloor[n][k] holds the result
     return egg_floor[n][k]

algorithms/dp/fib.py

@@ -1,17 +1,22 @@
 '''
-In mathematics, the Fibonacci numbers, commonly denoted Fn, form a sequence, called the Fibonacci sequence, 
-such that each number is the sum of the two preceding ones, starting from 0 and 1. 
+In mathematics, the Fibonacci numbers, commonly denoted Fn,
+form a sequence, called the Fibonacci sequence,
+such that each number is the sum of the two preceding ones,
+starting from 0 and 1.
 That is,
     F0=0 , F1=1
 and
     Fn= F(n-1) + F(n-2)
 The Fibonacci numbers are the numbers in the following integer sequence.
     0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, …….
 
-In mathematical terms, the sequence Fn of Fibonacci numbers is defined by the recurrence relation
+In mathematical terms, the sequence Fn of Fibonacci numbers is
+defined by the recurrence relation
 
 Here, given a number n, print n-th Fibonacci Number.
 '''
+
+
 def fib_recursive(n):
     """[summary]
     Computes the n-th fibonacci number recursive.
@@ -20,7 +25,7 @@ def fib_recursive(n):
 
     Arguments:
         n {[int]} -- [description]
-    
+
     Returns:
         [int] -- [description]
     """
@@ -35,15 +40,16 @@ def fib_recursive(n):
 
 # print(fib_recursive(35)) # => 9227465 (slow)
 
+
 def fib_list(n):
     """[summary]
     This algorithm computes the n-th fibbonacci number
     very quick. approximate O(n)
     The algorithm use dynamic programming.
-    
+
     Arguments:
         n {[int]} -- [description]
-    
+
     Returns:
         [int] -- [description]
     """
@@ -58,13 +64,14 @@ def fib_list(n):
 
 # print(fib_list(100)) # => 354224848179261915075
 
+
 def fib_iter(n):
     """[summary]
     Works iterative approximate O(n)
 
     Arguments:
         n {[int]} -- [description]
-    
+
     Returns:
         [int] -- [description]
     """

algorithms/dp/hosoya_triangle.py

@@ -8,38 +8,40 @@
 
 For example:
 printHosoya( 6 ) would return:
-1 
-1 1 
-2 1 2 
-3 2 2 3 
-5 3 4 3 5 
+1
+1 1
+2 1 2
+3 2 2 3
+5 3 4 3 5
 8 5 6 6 5 8
 
 The complexity is O(n^3).
 
 """
 
 
-def hosoya(n, m): 
+def hosoya(n, m):
     if ((n == 0 and m == 0) or (n == 1 and m == 0) or
-        (n == 1 and m == 1) or (n == 2 and m == 1)): 
+        (n == 1 and m == 1) or (n == 2 and m == 1)):
         return 1
-    if n > m: 
-        return hosoya(n - 1, m) + hosoya(n - 2, m) 
-    elif m == n: 
-        return hosoya(n - 1, m - 1) + hosoya(n - 2, m - 2) 
-    else: 
+    if n > m:
+        return hosoya(n - 1, m) + hosoya(n - 2, m)
+    elif m == n:
+        return hosoya(n - 1, m - 1) + hosoya(n - 2, m - 2)
+    else:
         return 0
-          
-def print_hosoya(n): 
-    for i in range(n): 
-        for j in range(i + 1): 
-            print(hosoya(i, j) , end = " ") 
-        print ("\n", end = "")
+
+
+def print_hosoya(n):
+    for i in range(n):
+        for j in range(i + 1):
+            print(hosoya(i, j), end=" ")
+        print("\n", end="")
+
 
 def hosoya_testing(n):
     x = []
-    for i in range(n): 
-        for j in range(i + 1): 
+    for i in range(n):
+        for j in range(i + 1):
             x.append(hosoya(i, j))
     return x