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

Author: brunohadlich

project_euler/problem_01/sol1.py

@@ -1,15 +1,17 @@
-'''
+"""
 Problem Statement:
 If we list all the natural numbers below 10 that are multiples of 3 or 5,
 we get 3,5,6 and 9. The sum of these multiples is 23.
 Find the sum of all the multiples of 3 or 5 below N.
-'''
+"""
 from __future__ import print_function
+
 try:
-    raw_input          # Python 2
+    raw_input  # Python 2
 except NameError:
     raw_input = input  # Python 3
 
+
 def solution(n):
     """Returns the sum of all the multiples of 3 or 5 below n.
     
@@ -27,5 +29,6 @@ def solution(n):
 
     return sum([e for e in range(3, n) if e % 3 == 0 or e % 5 == 0])
 
+
 if __name__ == "__main__":
     print(solution(int(raw_input().strip())))

project_euler/problem_01/sol2.py

@@ -1,15 +1,17 @@
-'''
+"""
 Problem Statement:
 If we list all the natural numbers below 10 that are multiples of 3 or 5,
 we get 3,5,6 and 9. The sum of these multiples is 23.
 Find the sum of all the multiples of 3 or 5 below N.
-'''
+"""
 from __future__ import print_function
+
 try:
-    raw_input          # Python 2
+    raw_input  # Python 2
 except NameError:
     raw_input = input  # Python 3
 
+
 def solution(n):
     """Returns the sum of all the multiples of 3 or 5 below n.
     
@@ -24,13 +26,14 @@ def solution(n):
     """
 
     sum = 0
-    terms = (n-1)//3
-    sum+= ((terms)*(6+(terms-1)*3))//2 #sum of an A.P.
-    terms = (n-1)//5
-    sum+= ((terms)*(10+(terms-1)*5))//2
-    terms = (n-1)//15
-    sum-= ((terms)*(30+(terms-1)*15))//2
+    terms = (n - 1) // 3
+    sum += ((terms) * (6 + (terms - 1) * 3)) // 2  # sum of an A.P.
+    terms = (n - 1) // 5
+    sum += ((terms) * (10 + (terms - 1) * 5)) // 2
+    terms = (n - 1) // 15
+    sum -= ((terms) * (30 + (terms - 1) * 15)) // 2
     return sum
 
+
 if __name__ == "__main__":
     print(solution(int(raw_input().strip())))

project_euler/problem_01/sol3.py

@@ -1,18 +1,22 @@
-'''
+"""
 Problem Statement:
 If we list all the natural numbers below 10 that are multiples of 3 or 5,
 we get 3,5,6 and 9. The sum of these multiples is 23.
 Find the sum of all the multiples of 3 or 5 below N.
-'''
+"""
 from __future__ import print_function
+
 try:
-    raw_input          # Python 2
+    raw_input  # Python 2
 except NameError:
     raw_input = input  # Python 3
 
-"""This solution is based on the pattern that the successive numbers in the series follow: 0+3,+2,+1,+3,+1,+2,+3."""
+
 def solution(n):
-    """Returns the sum of all the multiples of 3 or 5 below n.
+    """
+    This solution is based on the pattern that the successive numbers in the
+    series follow: 0+3,+2,+1,+3,+1,+2,+3.
+    Returns the sum of all the multiples of 3 or 5 below n.
     
     >>> solution(3)
     0
@@ -24,38 +28,39 @@ def solution(n):
     83700
     """
 
-    sum=0
-    num=0
-    while(1):
-        num+=3
-        if(num>=n):
+    sum = 0
+    num = 0
+    while 1:
+        num += 3
+        if num >= n:
             break
-        sum+=num
-        num+=2
-        if(num>=n):
+        sum += num
+        num += 2
+        if num >= n:
             break
-        sum+=num
-        num+=1
-        if(num>=n):
+        sum += num
+        num += 1
+        if num >= n:
             break
-        sum+=num
-        num+=3
-        if(num>=n):
+        sum += num
+        num += 3
+        if num >= n:
             break
-        sum+=num
-        num+=1
-        if(num>=n):
+        sum += num
+        num += 1
+        if num >= n:
             break
-        sum+=num
-        num+=2
-        if(num>=n):
+        sum += num
+        num += 2
+        if num >= n:
             break
-        sum+=num
-        num+=3
-        if(num>=n):
+        sum += num
+        num += 3
+        if num >= n:
             break
-        sum+=num
+        sum += num
     return sum
 
+
 if __name__ == "__main__":
     print(solution(int(raw_input().strip())))

project_euler/problem_01/sol4.py

@@ -1,15 +1,17 @@
-'''
+"""
 Problem Statement:
 If we list all the natural numbers below 10 that are multiples of 3 or 5,
 we get 3,5,6 and 9. The sum of these multiples is 23.
 Find the sum of all the multiples of 3 or 5 below N.
-'''
+"""
 from __future__ import print_function
+
 try:
-    raw_input          # Python 2
+    raw_input  # Python 2
 except NameError:
     raw_input = input  # Python 3
 
+
 def solution(n):
     """Returns the sum of all the multiples of 3 or 5 below n.
     
@@ -30,21 +32,22 @@ def solution(n):
     temp = 1
     while True:
         result = z * temp
-        if (result < n):
+        if result < n:
             zmulti.append(result)
             temp += 1
         else:
             temp = 1
             break
     while True:
         result = x * temp
-        if (result < n):
+        if result < n:
             xmulti.append(result)
             temp += 1
         else:
             break
-    collection = list(set(xmulti+zmulti))
-    return (sum(collection))
+    collection = list(set(xmulti + zmulti))
+    return sum(collection)
+
 
 if __name__ == "__main__":
     print(solution(int(raw_input().strip())))

project_euler/problem_01/sol5.py

@@ -1,16 +1,19 @@
-'''
+"""
 Problem Statement:
 If we list all the natural numbers below 10 that are multiples of 3 or 5,
 we get 3,5,6 and 9. The sum of these multiples is 23.
 Find the sum of all the multiples of 3 or 5 below N.
-'''
+"""
 from __future__ import print_function
+
 try:
-    raw_input          # Python 2
+    raw_input  # Python 2
 except NameError:
     raw_input = input  # Python 3
 
 """A straightforward pythonic solution using list comprehension"""
+
+
 def solution(n):
     """Returns the sum of all the multiples of 3 or 5 below n.
     
@@ -24,7 +27,8 @@ def solution(n):
     83700
     """
 
-    return sum([i for i in range(n) if i%3==0 or i%5==0])
+    return sum([i for i in range(n) if i % 3 == 0 or i % 5 == 0])
+
 
 if __name__ == "__main__":
     print(solution(int(raw_input().strip())))

project_euler/problem_01/sol6.py

@@ -1,15 +1,17 @@
-'''
+"""
 Problem Statement:
 If we list all the natural numbers below 10 that are multiples of 3 or 5,
 we get 3,5,6 and 9. The sum of these multiples is 23.
 Find the sum of all the multiples of 3 or 5 below N.
-'''
+"""
 from __future__ import print_function
+
 try:
-    raw_input          # Python 2
+    raw_input  # Python 2
 except NameError:
     raw_input = input  # Python 3
 
+
 def solution(n):
     """Returns the sum of all the multiples of 3 or 5 below n.
     
@@ -26,12 +28,13 @@ def solution(n):
     a = 3
     result = 0
     while a < n:
-        if(a % 3 == 0 or a % 5 == 0):
+        if a % 3 == 0 or a % 5 == 0:
             result += a
-        elif(a % 15 == 0):
+        elif a % 15 == 0:
             result -= a
         a += 1
     return result
 
+
 if __name__ == "__main__":
     print(solution(int(raw_input().strip())))

project_euler/problem_02/sol1.py

@@ -1,20 +1,25 @@
-'''
+"""
 Problem:
-Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2,
-the first 10 terms will be:
-                1,2,3,5,8,13,21,34,55,89,..
-By considering the terms in the Fibonacci sequence whose values do not exceed n, find the sum of the even-valued terms.
-e.g. for n=10, we have {2,8}, sum is 10.
-'''
+Each new term in the Fibonacci sequence is generated by adding the previous two
+terms. By starting with 1 and 2, the first 10 terms will be:
+
+    1,2,3,5,8,13,21,34,55,89,..
+
+By considering the terms in the Fibonacci sequence whose values do not exceed
+n, find the sum of the even-valued terms. e.g. for n=10, we have {2,8}, sum is
+10.
+"""
 from __future__ import print_function
 
 try:
-    raw_input          # Python 2
+    raw_input  # Python 2
 except NameError:
     raw_input = input  # Python 3
 
+
 def solution(n):
-    """Returns the sum of all fibonacci sequence even elements that are lower or equals to n.
+    """Returns the sum of all fibonacci sequence even elements that are lower
+    or equals to n.
     
     >>> solution(10)
     10
@@ -27,15 +32,16 @@ def solution(n):
     >>> solution(34)
     44
     """
-    i=1
-    j=2 
-    sum=0
-    while(j<=n):
-        if j%2 == 0:
-            sum+=j
-        i , j = j, i+j
+    i = 1
+    j = 2
+    sum = 0
+    while j <= n:
+        if j % 2 == 0:
+            sum += j
+        i, j = j, i + j
 
     return sum
 
+
 if __name__ == "__main__":
     print(solution(int(raw_input().strip())))

project_euler/problem_02/sol2.py

@@ -1,20 +1,25 @@
-'''
+"""
 Problem:
-Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2,
-the first 10 terms will be:
-                1,2,3,5,8,13,21,34,55,89,..
-By considering the terms in the Fibonacci sequence whose values do not exceed n, find the sum of the even-valued terms.
-e.g. for n=10, we have {2,8}, sum is 10.
-'''
+Each new term in the Fibonacci sequence is generated by adding the previous two
+terms. By starting with 1 and 2, the first 10 terms will be:
+
+    1,2,3,5,8,13,21,34,55,89,..
+
+By considering the terms in the Fibonacci sequence whose values do not exceed
+n, find the sum of the even-valued terms. e.g. for n=10, we have {2,8}, sum is
+10.
+"""
 from __future__ import print_function
 
 try:
-    raw_input          # Python 2
+    raw_input  # Python 2
 except NameError:
     raw_input = input  # Python 3
 
+
 def solution(n):
-    """Returns the sum of all fibonacci sequence even elements that are lower or equals to n.
+    """Returns the sum of all fibonacci sequence even elements that are lower
+    or equals to n.
     
     >>> solution(10)
     [2, 8]
@@ -32,8 +37,9 @@ def solution(n):
     while b <= n:
         if b % 2 == 0:
             ls.append(b)
-        a, b = b, a+b
+        a, b = b, a + b
     return ls
 
+
 if __name__ == "__main__":
     print(solution(int(raw_input().strip())))