Update prime_sieve_eratosthenes.py

maths/prime_sieve_eratosthenes.py

@@ -1,49 +1,63 @@
 """
-Sieve of Eratosthenes
+# Sieve of Eratosthenes
 
-Input: n = 10
-Output: 2 3 5 7
+# Input: n = 10
+# Output: 2 3 5 7
 
-Input: n = 20
-Output: 2 3 5 7 11 13 17 19
+# Input: n = 20
+# Output: 2 3 5 7 11 13 17 19
 
-you can read in detail about this at
-https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
-"""
+# you can read in detail about this at
+# https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes
+# """
+
+
+# def prime_sieve_eratosthenes(num: int) -> list[int]:
+#     """
+#     Print the prime numbers up to n
 
+#     >>> prime_sieve_eratosthenes(10)
+#     [2, 3, 5, 7]
+#     >>> prime_sieve_eratosthenes(20)
+#     [2, 3, 5, 7, 11, 13, 17, 19]
+#     >>> prime_sieve_eratosthenes(2)
+#     [2]
+#     >>> prime_sieve_eratosthenes(1)
+#     []
+#     >>> prime_sieve_eratosthenes(-1)
+#     Traceback (most recent call last):
+#     ...
+#     ValueError: Input must be a positive integer
+#     """
 
-def prime_sieve_eratosthenes(num: int) -> list[int]:
-    """
-    Print the prime numbers up to n
+#     if num <= 0:
+#         raise ValueError("Input must be a positive integer")
 
-    >>> prime_sieve_eratosthenes(10)
-    [2, 3, 5, 7]
-    >>> prime_sieve_eratosthenes(20)
-    [2, 3, 5, 7, 11, 13, 17, 19]
-    >>> prime_sieve_eratosthenes(2)
-    [2]
-    >>> prime_sieve_eratosthenes(1)
-    []
-    >>> prime_sieve_eratosthenes(-1)
-    Traceback (most recent call last):
-    ...
-    ValueError: Input must be a positive integer
-    """
+#     primes = [True] * (num + 1)
 
-    if num <= 0:
-        raise ValueError("Input must be a positive integer")
+#     p = 2
+#     while p * p <= num:
+#         if primes[p]:
+#             for i in range(p * p, num + 1, p):
+#                 primes[i] = False
+#         p += 1
 
-    primes = [True] * (num + 1)
+#     return [prime for prime in range(2, num + 1) if primes[prime]]
 
-    p = 2
-    while p * p <= num:
-        if primes[p]:
-            for i in range(p * p, num + 1, p):
-                primes[i] = False
-        p += 1
+def sieve(n):
+    isprime[0] = isprime[1] = False
+    for i in range(2, math.sqrt(n) + 1):
+        if isprime[i]:
+            primes.append(i)
+            for j in range(i*i, n+1, i):
+                isprime[j] = False
 
-    return [prime for prime in range(2, num + 1) if primes[prime]]
+n = int(input())
+isprime = [True for i in range(n+1)]
+primes = []
 
+print('The prime numbers from 1 to', n, 'are:')
+print(*primes)
 
 if __name__ == "__main__":
     import doctest
@@ -51,4 +65,4 @@
     doctest.testmod()
 
     user_num = int(input("Enter a positive integer: ").strip())
     print(prime_sieve_eratosthenes(user_num))