Solve problem

src/task23 - Non-abundant sums.py

@@ -1,10 +1,7 @@
-import math
-from functools import reduce
-
 def factors(x):
     result = [1]
     i = 2
-    while i*i <= x: #Other way of writing i<=sqrt(x)
+    while i*i <= x:
         if x % i == 0:
             result.append(i)
             if x//i != i:
@@ -12,39 +9,18 @@ def factors(x):
         i += 1
     return result
 
-def is_abundant(n):
-    return sum(factors(n)) > n
+def isAbundant(x):
+  return sum(factors(x)) > x
 
-abundants= [i for i in range(28123) if is_abundant(i)]
+abundantNumbers = [num for num in range(1, 28123) if isAbundant(num)]
+sums = [True for _ in range(1,28123)]
 
-range28 = [range(28123+1)]
-abundantsums = []
-result = []
-for i in range(len(abundants)):
-    for j in range(len(abundants)-i):
-        if abundants[i]+abundants[i-j]<=28123 and abundants[i]+abundants[i-j] in range28:
-            abundantsums.append(abundants[i]+abundants[i-j])
-            range28.pop(range28.index(abundants[i]+abundants[i-j]))
-            result.append(abundants[i]+abundants[i-j])
-print(len(abundantsums)) #24 266 061
-print("calculated abundantsums")
+for i in range(len(abundantNumbers)):
+  for k in range(len(abundantNumbers)):
+    try:
+      sums[abundantNumbers[i] + abundantNumbers[k]] = False
+    except IndexError:
+      pass
 
-
-
-#result = sum([i for i in range(28123+1) if not i in abundantsums])
-
-# result = 0
-# for i in range(28123+1):
-#     print(i)
-#     if not i in abundantsums:
-#         result+=i
-
-# range28 = [range(28123+1)]
-# result = []
-# for i in abundantsums:
-#     if i in range28:
-#         range28.pop(range28.index(i))
-#         result.append(i)
-
-print(result)
+print(sum([i for i, x in enumerate(sums) if x]))
 

src/task26 - Reciprocal cycles.py

@@ -1,4 +1,16 @@
 
-for i in range(1,1000):
-    x = 1/i
-    
+
+numsWithRecurringCycles = [n for n in range(2,1000) if n % 2 != 0 and n % 5 != 0]
+
+def digits(num, divisor):
+  x = num
+  storedSums = []
+  while not x*10 in storedSums:
+    x *= 10
+    storedSums.append(x)
+    x %= divisor
+  return len(storedSums)
+
+digitNumList = [digits(1, n) for n in numsWithRecurringCycles]
+
+print(numsWithRecurringCycles[digitNumList.index(max(digitNumList))])

src/task32 - Pandigital products.py

@@ -1,16 +1,14 @@
-totalSum=0
-usedFactors = []
-for i in range(1, 10000):
-    if i%100==0:
-        print(str(i/100) + "%")
-    for j in range(1, 10000):
-        x=i*j
-        if len(str(i))+len(str(j))+len(str(x))==9:
-            result = sum([int(k) for k in str(x)])
-            result += sum([int(k) for k in str(i)])
-            result += sum([int(k) for k in str(j)])
-            if sum==1+2+3+4+5+6+7+8+9:
-                totalSum+=x
+from itertools import permutations
+from math import ceil
 
-print(totalSum)
-#HINT: Some products can be obtained in more than one way so be sure to only include it once in your sum.
+def isPanDigital(i,j,x):
+  return sorted(str(i) + str(j) + str(x)) == ['1' ,'2', '3', '4', '5', '6', '7', '8', '9']
+
+panDigits = []
+for i in range(1,10000):
+  for j in range(1,ceil(10000/i)):
+    prod = i*j
+    if isPanDigital(i, j, prod) and not prod in panDigits:
+      panDigits.append(prod)
+
+print(sum(panDigits))

src/task62 - Cubic permutations.py

@@ -0,0 +1,18 @@
+def has5Permutations(n):
+  return numberList[len(n)].count(n) == 5
+
+numberList = [[] for _ in range(100)]
+
+i=1
+while True:
+
+  n = i**3
+  sortedN = ''.join(sorted(str(n)))
+  numberList[len(sortedN)].append(sortedN)
+
+  if has5Permutations(sortedN):
+    index = numberList[len(sortedN)].index(sortedN)
+    print((sum([len(numberList[j]) for j in range(len(sortedN)) ]) + index+1) ** 3)
+    exit(0)
+
+  i += 1