Change the Graph testing to use JUnit

Author: Justin Wetherell

src/com/jwetherell/algorithms/mathematics/Distance.java

@@ -2,8 +2,7 @@
 
 public class Distance {
 
-    private Distance() {
-    }
+    private Distance() { }
 
     /*
      * Chess distance
@@ -13,7 +12,7 @@ public static final long chebyshevDistance(long[] point1, long[] point2) {
         long y1 = point1[1];
         long x2 = point2[0];
         long y2 = point2[1];
-        return (int) Math.max(Math.abs(x1 - x2), Math.abs(y1 - y2));
+        return Math.max(Math.abs(x1 - x2), Math.abs(y1 - y2));
     }
 
     public static final double squaredDistance(double x1, double y1, double x2, double y2) {

src/com/jwetherell/algorithms/mathematics/Primes.java

@@ -1,5 +1,6 @@
 package com.jwetherell.algorithms.mathematics;
 
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -74,17 +75,22 @@ public static final boolean isPrime(long value) {
     public static final boolean sieveOfEratosthenes(int number) {
         if (sieve == null || number >= sieve.length) {
             int start = 2;
-            if (sieve == null)
-                sieve = new boolean[number];
-            else
+            if (sieve == null) {
+                sieve = new boolean[number+1];
+            } else if (number >= sieve.length) {
+                sieve = Arrays.copyOf(sieve, number+1);
                 start = sieve.length;
-            for (int i = start; Math.pow(i, 2) < sieve.length; i++) {
+            }
+            sieve[0] = true;
+            sieve[1] = false;
+            for (int i = start; (int) Math.pow(i, 2) < sieve.length; i++) {
                 if (!sieve[i]) {
                     for (int j = (int) Math.pow(i, 2); j < sieve.length; j += i) {
                         sieve[j] = true;
                     }
                 }
             }
+            sieve[2] = true;
         }
         return !sieve[number];
     }