Added SieveOfEratosthenes.java

Others/SieveOfEratosthenes.java

@@ -0,0 +1,49 @@
+/**
+ *
+ * @author Varun Upadhyay (https://github.com/varunu28)
+ *
+ */
+public class SieveOfEratosthenes {
+
+    /**
+     * This method implements the Sieve of Eratosthenes Algorithm
+     *
+     * @param n The number till which we have to check for prime
+     * Prints all the prime numbers till n
+     **/
+
+    public static void findPrimesTillN(int n) {
+        int[] arr = new int[n+1];
+
+        for (int i=0;i<=n;i++) {
+            arr[i] = 1;
+        }
+
+        arr[0] = arr[1] = 0;
+
+        for (int i=2;i<=Math.sqrt(n);i++) {
+            if (arr[i] == 1) {
+                for (int j=2;i*j <= n;j++) {
+                    arr[i*j] = 0;
+                }
+            }
+        }
+
+        for (int i=0;i<n+1;i++) {
+            if (arr[i] == 1) {
+                System.out.print(i + " ");
+            }
+        }
+
+        System.out.println();
+    }
+
+    // Driver Program
+    public static void main(String[] args) {
+        int n = 100;
+
+        // Prints 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97 
+        findPrimesTillN(n);
+    }
+
+}