unsuccessful in finding solution to PE 100 with integer square root idea...

100/FindBlues.java

@@ -0,0 +1,38 @@
+public class FindBlues {
+
+	public static void main(String[] args) { 
+		findSolutions((long)(1E12));
+	}
+
+	/** Find solutions to the problem of 
+	 * how many blue records to have so that 
+	 * two blue records taken at random have 
+	 * 50% probability.
+	 */
+	public static void findSolutions(long originalN) { 
+		long N = originalN;
+		int count = 0;
+		boolean done = false;
+		while(!done) { 
+			N++;
+			count++;
+			long operand = 2*N*(N-1)+1;
+			long squirt = (long)(Math.sqrt(operand));
+			if(squirt*squirt == operand) { 
+				if(squirt%2==1) { 
+					System.out.println("Found solution.");
+					break;
+				}
+			}
+		}
+		long operand = 2*N*(N-1)+1;
+		long NB = (long)(Math.sqrt(operand));
+		System.out.println("N:\t"+N);
+		System.out.println("NB:\t"+NB);
+
+		// Nope....
+
+	}
+
+}
+