Data commit

Task/Sisyphus-sequence/Python/sisyphus-sequence-1.py

@@ -0,0 +1,73 @@
+from collections import Counter
+from itertools import islice
+from typing import Iterable
+from typing import Iterator
+from typing import Tuple
+from typing import TypeVar
+
+import primesieve
+
+
+def primes() -> Iterator[int]:
+    it = primesieve.Iterator()
+    while True:
+        yield it.next_prime()
+
+
+def sisyphus() -> Iterator[Tuple[int, int]]:
+    prime = primes()
+    n = 1
+    p = 0
+    yield n, p
+
+    while True:
+        if n % 2:
+            p = next(prime)
+            n = n + p
+        else:
+            n = n // 2
+        yield n, p
+
+
+def consume(it: Iterator[Tuple[int, int]], n) -> Tuple[int, int]:
+    next(islice(it, n - 1, n - 1), None)
+    return next(it)
+
+
+T = TypeVar("T")
+
+
+def batched(it: Iterable[T], n: int) -> Iterable[Tuple[T, ...]]:
+    _it = iter(it)
+    batch = tuple(islice(_it, n))
+    while batch:
+        yield batch
+        batch = tuple(islice(_it, n))
+
+
+if __name__ == "__main__":
+    it = sisyphus()
+    first_100 = list(islice(it, 100))
+    print("The first 100 members of the Sisyphus sequence are:")
+    for row in batched(first_100, 10):
+        print("  ".join(str(n).rjust(3) for n, _ in row))
+
+    print("")
+
+    for interval in [10**x for x in range(3, 9)]:
+        n, prime = consume(it, interval - (interval // 10))
+        print(f"{interval:11,}th number: {n:13,}   highest prime needed: {prime:11,}")
+
+    print("")
+
+    sisyphus_lt_250 = Counter(n for n, _ in islice(sisyphus(), 10**8) if n < 250)
+    print("These numbers under 250 do not occur in the first 100,000,000 terms:")
+    print(" ", [n for n in range(1, 250) if n not in sisyphus_lt_250])
+    print("")
+
+    most_common = sisyphus_lt_250.most_common(1)[0][1]
+    print("These numbers under 250 occur the most in the first 100,000,000 terms:")
+    print(
+        f"  {[n for n, c in sisyphus_lt_250.items() if c == most_common]} "
+        f"all occur {most_common} times."
+    )

Task/Sisyphus-sequence/Python/sisyphus-sequence-2.py

@@ -0,0 +1,22 @@
+import primesieve
+
+def sisyphus36():
+    primes = primesieve.Iterator()
+    n = 1
+    p = 0
+    i = 1
+
+    while True:
+        i += 1
+        if n % 2:
+            p = primes.next_prime()
+            n = n + p
+        else:
+            n = n // 2
+
+        if n == 36:
+            print(f"{i:,}, {n:,}, {p:,}")
+            break
+
+if __name__ == "__main__":
+    sisyphus36()