Merge pull request #10 from bhansa/master

Added new method for sieve of Eratosthenes

Author: prateekiiest

Diff for: Prime/code.py

@@ -1,30 +1,46 @@
+def SieveOfEratosthenes(range_to):
 
+  # creating a boolean array first
+  prime = [True for i in range(range_to + 1)]
+  p = 2
+  while (p * p <= range_to):
+       
+    # If prime[p] is not changed, then it is a prime
+    if (prime[p] == True):
+         
+        # Update all multiples of p
+        for i in range(p * 2, range_to + 1, p):
+            prime[i] = False
+    p += 1
+  print([p for p in range(2, range_to) if prime[p]])
 
 def prime(range_from, range_to):
 
-  allList = [x for x in range(2, int(range_to)+1)]
+  allList = [x for x in range(2, range_to + 1)]
 
   ptr = 0
   while True:
     i = 2
-    while i * allList[ptr] <= int(range_to):
+    while i * allList[ptr] <= range_to:
       if i*allList[ptr] in allList:
         allList.remove(i*allList[ptr])
       i += 1
     ptr += 1
-    if allList[ptr] ** 2 > int(range_to):
+    if allList[ptr] ** 2 > range_to:
       break
 
 
-  primeList = [x for x in allList if x > int(range_from)]
+  primeList = [x for x in allList if x > range_from]
   print("Prime List Between ", range_from, " and ", range_to, " is")
   print(primeList)
 
 
 
 if __name__ == "__main__":
   print("Enter the range of number")
-  range_from = input("From: ")
-  range_to = input("To: ")
+  range_from = int(input("From: "))
+  range_to = int(input("To: "))
 
   prime(range_from, range_to)
+  SieveOfEratosthenes(range_to)
+