2 files changed, 72 insertions, 0 deletions
diff --git a/sem5/oop/m2/primes/src/Main.java b/sem5/oop/m2/primes/src/Main.java
new file mode 100644
index 0000000..e191835
--- /dev/null
+++ b/sem5/oop/m2/primes/src/Main.java
@@ -0,0 +1,32 @@
+
+public class Main {
+
+	public static void main(String[] args) {
+		System.out.println("Lets find some primes!!");
+		
+		int runto = 10000;
+		if (args.length > 0) {
+			runto = Integer.parseInt(args[0]);
+		}
+		
+		// Calculate length of runto as string
+		int numlen = String.valueOf(runto).length();
+		
+		PrimeGen pg = new PrimeGen();
+		
+		int p;
+		int index = 1;
+		while ((p = pg.next(runto)) != -1) {
+			// Terrible two level format
+			System.out.printf(String.format("%%-%dd ", numlen), p);
+			if (index % 10 == 0) {
+				System.out.print(System.lineSeparator());
+			}
+			index++;
+		}
+		System.out.print(System.lineSeparator());
+		System.out.printf("Found %d primes%n", index-1);
+
+	}
+
+}
diff --git a/sem5/oop/m2/primes/src/PrimeGen.java b/sem5/oop/m2/primes/src/PrimeGen.java
new file mode 100644
index 0000000..9c91645
--- /dev/null
+++ b/sem5/oop/m2/primes/src/PrimeGen.java
@@ -0,0 +1,40 @@
+import java.io.PrintStream;
+import java.util.ArrayList;
+
+public class PrimeGen {
+	
+	private ArrayList<Integer> primes;
+	private int at;
+
+	public PrimeGen() {
+		this.primes = new ArrayList<>();
+		
+		this.at = 1;
+	}
+	
+	public int next(int limit) {
+		// Run until a prime
+		primeloop:
+		while (true) {
+			this.at++;
+			if (this.at >= limit) {
+				return -1;
+			}
+
+			for (int prime : this.primes) {
+				if (this.at % prime == 0) {
+					continue primeloop;
+				}
+			}
+			break;
+		}
+	
+		this.primes.add(at);
+		return at;
+	}
+	
+	public int next() {
+		return next(-1);
+	}
+	
+}