Merge pull request #372 from ushmita4/master

#279  Add Sieve of Eratosthenes in C language

Author: smv1999

Numbers/Sieve.c

@@ -0,0 +1,40 @@
+#include <stdio.h>
+
+int main()
+{
+    int number,i,j;
+    printf("Enter the number\n");
+    scanf("%d",&number);
+
+    int primes[number+1];
+
+    //populating array with naturals numbers
+    for(i = 2; i<=number; i++)
+        primes[i] = i;
+
+    i = 2;
+    while ((i*i) <= number)
+    {
+        if (primes[i] != 0)
+        {
+            for(j=2; j<number; j++)
+            {
+                if (primes[i]*j > number)
+                    break;
+                else
+                    // Instead of deleteing , making elemnets 0
+                    primes[primes[i]*j]=0;
+            }
+        }
+        i++;
+    }
+      printf("The prime numbers are\n");
+    for(i = 2; i<=number; i++)
+    {
+        //If number is not 0 then it is prime
+        if (primes[i]!=0)
+            printf("%d\t",primes[i]);
+    }
+
+    return 0;
+}