Finished existing ipython solutions to python. Ready to continue in pure python.

python/e057.py

@@ -1,8 +1,31 @@
+from lib_misc import gcd
+from lib_misc import get_digit_count
+
+
+def add_fractions(n1, d1, n2, d2):
+    d = d1 * d2
+    n1 = n1 * (d // d1)
+    n2 = n2 * (d // d2)
+    n = n1 + n2
+    p = gcd(n, d)
+    return (n // p, d // p)
+
+
+def next_expension(n, d):
+    n, d = add_fractions(1, 1, n, d)
+    return add_fractions(1, 1, d, n)
+
 
 def euler_057():
-    return 0
+    c = 0
+    n, d = (3, 2)
+    for i in range(1000):
+        if get_digit_count(n) > get_digit_count(d):
+            c += 1
+        n, d = next_expension(n, d)
+    return c
 
 
 if __name__ == "__main__":
     print("e057.py: " + str(euler_057()))
-    assert(euler_057() == 0)
+    assert(euler_057() == 153)

python/e058.py

@@ -1,8 +1,33 @@
+from lib_prime import is_prime
+
+
+def get_corner_values(side_length):
+    def get_last_corner_value(side_length):
+        return side_length * side_length
+
+    if side_length == 1:
+        return [1]
+    return [get_last_corner_value(side_length) - i * (side_length - 1)
+            for i in range(0, 4)][::-1]
+
 
 def euler_058():
-    return 0
+    n = 1
+    count_primes = 0
+    count_total = 0
+    while True:
+        for v in get_corner_values(n):
+            count_total += 1
+            if is_prime(v):
+                count_primes += 1
+        ratio = count_primes / count_total
+        if ratio != 0 and ratio < 0.10:
+            # print("n: {} count_total: {} count_primes: {} ratio: {}"
+            # .format(n, count_total, count_primes, ratio))
+            return n
+        n += 2
 
 
 if __name__ == "__main__":
     print("e058.py: " + str(euler_058()))
-    assert(euler_058() == 0)
+    assert(euler_058() == 26241)

python/e059.py

@@ -1,8 +1,61 @@
 
+def get_encrypted_msg():
+    with open("../txt/EulerProblem059.txt", "r") as f:
+        msg = [int(d) for d in f.read().split(',')]
+        return msg
+
+
+def get_words():
+    with open("../txt/EulerProblem042.txt", "r") as f:
+        words = [w.strip('"') for w in f.read().split(",")]
+        return set(words)
+
+
+def generate_keys():
+    alphabet = list(map(chr, range(97, 123)))
+    return [(ord(a), ord(b), ord(c))
+            for a in alphabet
+            for b in alphabet
+            for c in alphabet]
+
+
+def to_string(msg):
+    return "".join(map(chr, msg))
+
+
+def to_ascii(msg):
+    return list(map(ord, msg))
+
+
+def decrypt_msg(key, msg):
+    return [d ^ key[i % len(key)] for i, d in enumerate(msg)]
+
+
+def clean_word(word):
+    return word.strip('').strip(",").strip(".").strip("!").strip("?").upper()
+
+
+def test_key(key, msg, word_list):
+    msg = to_string(decrypt_msg(key, msg))
+    word_count = 0
+    words = msg.split(" ")
+    for word in words:
+        if clean_word(word) in word_list:
+            word_count += 1
+    return word_count / len(words)
+
+
 def euler_059():
-    return 0
+    msg = get_encrypted_msg()
+    word_list = get_words()
+    keys = generate_keys()
+    ss = [(test_key(key, msg, word_list), key) for key in keys]
+    s = sorted(ss, reverse=True)[0]
+    key = s[1]
+    s = sum(decrypt_msg(key, msg))
+    return s
 
 
 if __name__ == "__main__":
     print("e059.py: " + str(euler_059()))
-    assert(euler_059() == 0)
+    assert(euler_059() == 107359)

python/e060.py

@@ -1,8 +1,55 @@
+from itertools import combinations
+from lib_prime import primes, is_prime
+
+
+def concatenate_all(numbers):
+    result = []
+    for a, b in combinations(numbers, 2):
+        result.append([a, b])
+        result.append([b, a])
+    return result
+
+
+def concatentation_is_prime(a, b):
+    ab = int(str(a) + str(b))
+    ba = int(str(b) + str(a))
+    if is_prime(ab) and is_prime(ba):
+        return True
+    else:
+        return False
+
 
 def euler_060():
-    return 0
+    """ Hahaha. I have no idea what I was thinking
+    when writing this code. Beautiful! """
+    potentials = []
+    new_potentials = []
+    done = False
+    for p in primes(100000):
+        if done:
+            break
+        potentials += new_potentials
+        new_potentials = []
+        for potential in potentials:
+            all_concatenations_prime = True
+            for prime in potential:
+                if not concatentation_is_prime(p, prime):
+                    all_concatenations_prime = False
+                    break
+            if all_concatenations_prime:
+                new_potential = list(potential)
+                new_potential.append(p)
+                if len(new_potential) > 4:
+                    # print(new_potential)
+                    s = sum(new_potential)
+                    done = True
+                    break
+                new_potentials.append(new_potential)
+        if p < 15:
+            potentials.append([p])
+    return s
 
 
 if __name__ == "__main__":
     print("e060.py: " + str(euler_060()))
-    assert(euler_060() == 0)
+    assert(euler_060() == 26033)

python/e061.py

@@ -1,8 +1,59 @@
+def get_four_digit_numbers(function):
+    r = []
+    n = 1
+    f = function
+    while f(n) < 10000:
+        if f(n) > 999:
+            r.append(f(n))
+        n += 1
+    return r
+
+
+def search_solution(aggregator, polygonals):
+    if not polygonals:
+        if is_cyclic(aggregator[-1], aggregator[0]):
+            return aggregator
+        else:
+            return []
+
+    if not aggregator:
+        for polygonal in polygonals:
+            for number in polygonal:
+                aggregator.append(number)
+                s = search_solution(
+                    aggregator, [p for p in polygonals if p != polygonal])
+                if s:
+                    return s
+                aggregator.pop()
+
+    for polygonal in polygonals:
+        for number in polygonal:
+            if is_cyclic(aggregator[-1], number) and number not in aggregator:
+                aggregator.append(number)
+                s = search_solution(
+                    aggregator, [p for p in polygonals if p != polygonal])
+                if s:
+                    return s
+                aggregator.pop()
+    return []
+
+
+def is_cyclic(a, b):
+    return str(a)[-2:] == str(b)[:2]
+
 
 def euler_061():
-    return 0
+    triangles = get_four_digit_numbers(lambda n: n * (n + 1) // 2)
+    squares = get_four_digit_numbers(lambda n: n**2)
+    pentas = get_four_digit_numbers(lambda n: n * (3 * n - 1) // 2)
+    hexas = get_four_digit_numbers(lambda n: n * (2 * n - 1))
+    heptas = get_four_digit_numbers(lambda n: n * (5 * n - 3) // 2)
+    octas = get_four_digit_numbers(lambda n: n * (3 * n - 2))
+    s = search_solution([], [triangles, squares, pentas, hexas, heptas, octas])
+    s = sum(s)
+    return s
 
 
 if __name__ == "__main__":
     print("e061.py: " + str(euler_061()))
-    assert(euler_061() == 0)
+    assert(euler_061() == 28684)

python/e062.py

@@ -1,8 +1,20 @@
 
 def euler_062():
-    return 0
+    solutions = {}
+    for n in range(1, 10000):
+        cube = n * n * n
+        try:
+            key = "".join(sorted(str(cube)))
+            solutions[key].append(cube)
+            if len(solutions[key]) > 4:
+                # print(solutions[key])
+                s = solutions[key][0]
+                break
+        except KeyError:
+            solutions[key] = [cube]
+    return s
 
 
 if __name__ == "__main__":
     print("e062.py: " + str(euler_062()))
-    assert(euler_062() == 0)
+    assert(euler_062() == 127035954683)

python/e063.py

@@ -1,8 +1,22 @@
+from lib_misc import get_digit_count
+
+
+def get_n_digit_positive_integers(n):
+    r = []
+    i = 1
+    while True:
+        if get_digit_count(i ** n) == n:
+            r.append(i ** n)
+        if get_digit_count(i ** n) > n:
+            return r
+        i += 1
+
 
 def euler_063():
-    return 0
+    s = sum([len(get_n_digit_positive_integers(n)) for n in range(1, 1000)])
+    return s
 
 
 if __name__ == "__main__":
     print("e063.py: " + str(euler_063()))
-    assert(euler_063() == 0)
+    assert(euler_063() == 49)

python/e064.py

@@ -1,8 +1,69 @@
+import math
+
+
+def get_floor_sqrt(n):
+    return math.floor(math.sqrt(n))
+
+
+def next_expansion(current_a, current_nominator,
+                   current_denominator, original_number):
+    # Less typing
+    cn = current_nominator
+    cd = current_denominator
+
+    # Step 1: Multiply the fraction so that we can use the third binomial
+    # formula. Make sure we can reduce the nominator.
+    assert((original_number - cd * cd) % cn == 0)
+    # The new nominator is the denominator since we multiply with (x + cd) and
+    # then reduce the previous nominator. The new denominator is calculated by
+    # applying the third binomial formula and then by divided by the previous
+    # nominator.
+    cn, cd = cd, (original_number - cd * cd) // cn
+
+    # Step 2: Calculate the next a by finding the next floor square root.
+    next_a = math.floor((math.sqrt(original_number) + cn) // cd)
+
+    # Step 3: Remove next a from the fraction by substracting it.
+    cn = cn - next_a * cd
+    cn *= -1
+
+    return next_a, cn, cd
+
+
+def get_continued_fraction_sequence(n):
+
+    # If number is a square number we return it.
+    floor_sqrt = get_floor_sqrt(n)
+    if n == floor_sqrt * floor_sqrt:
+        return ((floor_sqrt), [])
+
+    # Otherwise, we calculate the next expansion till we
+    # encounter a step a second time.
+    a = floor_sqrt
+    cn = a
+    cd = 1
+    sequence = []
+    previous_steps = []
+
+    while not (a, cn, cd) in previous_steps:
+        # print("a: {} cn: {} cd: {}".format(a, cn, cd))
+        previous_steps.append((a, cn, cd))
+        a, cn, cd = next_expansion(a, cd, cn, n)
+        sequence.append(a)
+    sequence.pop()
+    return ((floor_sqrt), sequence)
+
+
+def get_period(n):
+    _, sequence = get_continued_fraction_sequence(n)
+    return len(sequence)
+
 
 def euler_064():
-    return 0
+    s = len([n for n in range(1, 10001) if get_period(n) % 2 != 0])
+    return s
 
 
 if __name__ == "__main__":
     print("e064.py: " + str(euler_064()))
-    assert(euler_064() == 0)
+    assert(euler_064() == 1322)

python/e065.py

@@ -1,8 +1,21 @@
+from e057 import add_fractions
+
+
+def next_expansion(previous_numerator, previous_denumerator, value):
+    if previous_numerator == 0:
+        return (value, 1)
+    return add_fractions(previous_denumerator, previous_numerator, value, 1)
+
 
 def euler_065():
-    return 0
+    e_sequence = [2] + [n for i in range(2, 1000, 2) for n in (1, i, 1)]
+    n, d = 0, 1
+    for i in range(100, 0, -1):
+        n, d = next_expansion(n, d, e_sequence[i - 1])
+    s = sum([int(l) for l in str(n)])
+    return s
 
 
 if __name__ == "__main__":
     print("e065.py: " + str(euler_065()))
-    assert(euler_065() == 0)
+    assert(euler_065() == 272)

python/e066.py

@@ -1,8 +1,97 @@
+import math
+from e057 import add_fractions
+
+
+def get_floor_sqrt(n):
+    return math.floor(math.sqrt(n))
+
+
+def next_expansion_1(current_a, current_nominator,
+                     current_denominator, original_number):
+    cn = current_nominator
+    cd = current_denominator
+    cn, cd = cd, (original_number - cd * cd) // cn
+    next_a = math.floor((math.sqrt(original_number) + cn) // cd)
+    cn = cn - next_a * cd
+    cn *= -1
+
+    return next_a, cn, cd
+
+
+def get_continued_fraction_sequence(n):
+
+    # If number is a square number we return it.
+    floor_sqrt = get_floor_sqrt(n)
+    if n == floor_sqrt * floor_sqrt:
+        return ((floor_sqrt), [])
+
+    # Otherwise, we calculate the next expansion till we
+    # encounter a step a second time.
+    a = floor_sqrt
+    cn = a
+    cd = 1
+    sequence = []
+    previous_steps = []
+
+    while not (a, cn, cd) in previous_steps:
+        # print("a: {} cn: {} cd: {}".format(a, cn, cd))
+        previous_steps.append((a, cn, cd))
+        a, cn, cd = next_expansion_1(a, cd, cn, n)
+        sequence.append(a)
+    sequence.pop()
+    return ((floor_sqrt), sequence)
+
+
+def next_expansion_2(previous_numerator, previous_denumerator, value):
+    if previous_numerator == 0:
+        return (value, 1)
+    return add_fractions(previous_denumerator, previous_numerator, value, 1)
+
+
+def get_fractions(n, x):
+    # print("get_fractions(n={}, x={})".format(n, x))
+    # Get sequence of a_x
+    first_value, sequence = get_continued_fraction_sequence(n)
+    sequence = [first_value] + math.ceil(x / len(sequence)) * sequence
+    sequence = sequence[:x + 1]
+    sequence = sequence[::-1]
+
+    n, d = 0, 1
+    for s in sequence:
+        n, d = next_expansion_2(n, d, s)
+    return (n, d)
+
+
+def get_minimal_solution(d):
+    for i in range(0, 100):
+        x, y = get_fractions(d, i)
+        if x * x - d * y * y == 1:
+            return((x, y))
+
+
+def is_square(n):
+    return math.sqrt(n).is_integer()
+
 
 def euler_066():
-    return 0
+    # XXX: This seems really long and complicated. We can do better.
+    x_max = 0
+    d_max = 0
+
+    for d in range(2, 1001):
+        if is_square(d):
+            continue
+
+        x, y = get_minimal_solution(d)
+        if x > x_max:
+            x_max = x
+            d_max = d
+
+    print("d: {} x: {}".format(d_max, x_max))
+    s = d_max
+    return s
 
 
 if __name__ == "__main__":
     print("e066.py: " + str(euler_066()))
-    assert(euler_066() == 0)
+    assert(euler_066() == 661)

python/e068.py

@@ -1,5 +1,5 @@
-
 def euler_068():
+    # XXX: continue here
     return 0
 
 

python/lib_misc.py

@@ -196,7 +196,13 @@ def permutations(iterable):
 
 
 def gcd(a, b):
-    """ Returns the greatest commond divisor of a and b. """
-    if b == 0:
-        return a
-    return gcd(b, a % b)
+    while a % b != 0:
+        a, b = b, a % b
+    return b
+
+
+def get_digit_count(n):
+    """
+    Returns the number of digits for n.
+    """
+    return len(str(n))

python/lib_misc_tests.py

@@ -13,6 +13,7 @@ try:
     from .lib_misc import proper_divisors, sum_proper_divisors
     from .lib_misc import permutations
     from .lib_misc import gcd
+    from .lib_misc import get_digit_count
 except ModuleNotFoundError:
     from lib_misc import is_palindrome_integer
     from lib_misc import is_palindrome_string
@@ -27,6 +28,7 @@ except ModuleNotFoundError:
     from lib_misc import proper_divisors, sum_proper_divisors
     from lib_misc import permutations
     from lib_misc import gcd
+    from lib_misc import get_digit_count
 
 
 class TestPrimeMethods(unittest.TestCase):
@@ -131,6 +133,10 @@ class TestPrimeMethods(unittest.TestCase):
         self.assertEqual(gcd(15, 6), 3)
         self.assertEqual(gcd(6, 15), 3)
 
+    def test_get_digit_count(self):
+        self.assertEqual(get_digit_count(1), 1)
+        self.assertEqual(get_digit_count(1234567890), 10)
+
 
 if __name__ == '__main__':
     unittest.main()