From 1cbd689d39d85eaaa494e97c3d136933691c83fd Mon Sep 17 00:00:00 2001
From: jaebradley <jae.b.bradley@gmail.com>
Date: Wed, 19 Jul 2017 14:50:34 -0400
Subject: [PATCH 1/2] separate the numbers implementation

---
 .../BeautifulNumberValidatorImpl.java         | 37 +++++++++++++++++++
 .../interfaces/BeautifulNumberValidator.java  |  5 +++
 .../BeautifulNumberValidatorImplTest.java     | 30 +++++++++++++++
 3 files changed, 72 insertions(+)
 create mode 100644 src/main/java/algorithms/implementations/BeautifulNumberValidatorImpl.java
 create mode 100644 src/main/java/algorithms/interfaces/BeautifulNumberValidator.java
 create mode 100644 src/test/java/algorithms/implementations/BeautifulNumberValidatorImplTest.java

diff --git a/src/main/java/algorithms/implementations/BeautifulNumberValidatorImpl.java b/src/main/java/algorithms/implementations/BeautifulNumberValidatorImpl.java
new file mode 100644
index 0000000..3910685
--- /dev/null
+++ b/src/main/java/algorithms/implementations/BeautifulNumberValidatorImpl.java
@@ -0,0 +1,37 @@
+package algorithms.implementations;
+
+import algorithms.interfaces.BeautifulNumberValidator;
+
+/**
+ * https://www.hackerrank.com/challenges/separate-the-numbers/problem
+ */
+
+public class BeautifulNumberValidatorImpl implements BeautifulNumberValidator {
+  @Override
+  public boolean isValidBeautifulNumber(final String s) {
+    if (s.length() < 2) {
+      return false;
+    }
+
+    for (int substringSize = 1; substringSize <= s.length() / 2; substringSize++) {
+      long value = Long.parseLong(s.substring(0, substringSize));
+
+      if (value == 0) {
+        break;
+      }
+
+      StringBuilder sb = new StringBuilder();
+      sb.append(value);
+
+      while (sb.length() < s.length() && sb.toString().equals(s.substring(0, sb.length()))) {
+        sb.append(++value);
+      }
+
+      if (sb.toString().equals(s)) {
+        return true;
+      }
+    }
+
+    return false;
+  }
+}
diff --git a/src/main/java/algorithms/interfaces/BeautifulNumberValidator.java b/src/main/java/algorithms/interfaces/BeautifulNumberValidator.java
new file mode 100644
index 0000000..f79928f
--- /dev/null
+++ b/src/main/java/algorithms/interfaces/BeautifulNumberValidator.java
@@ -0,0 +1,5 @@
+package algorithms.interfaces;
+
+public interface BeautifulNumberValidator {
+  boolean isValidBeautifulNumber(final String s);
+}
diff --git a/src/test/java/algorithms/implementations/BeautifulNumberValidatorImplTest.java b/src/test/java/algorithms/implementations/BeautifulNumberValidatorImplTest.java
new file mode 100644
index 0000000..52a6ad7
--- /dev/null
+++ b/src/test/java/algorithms/implementations/BeautifulNumberValidatorImplTest.java
@@ -0,0 +1,30 @@
+package algorithms.implementations;
+
+import algorithms.interfaces.BeautifulNumberValidator;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+public class BeautifulNumberValidatorImplTest {
+  final BeautifulNumberValidator validator = new BeautifulNumberValidatorImpl();
+
+  @Test
+  public void itShouldBeAValidBeautifulNumber() {
+    assertTrue(validator.isValidBeautifulNumber("1234"));
+  }
+
+  @Test
+  public void itShouldNotBeAValidBeautifulNumber() {
+    assertFalse(validator.isValidBeautifulNumber("101103"));
+  }
+
+  @Test
+  public void itShouldNotBeAValidBeautifulNumberSinceItStartsWithZero() {
+    assertFalse(validator.isValidBeautifulNumber("010203"));
+  }
+
+  @Test
+  public void itShouldNotBeAValidBeautifulNumberSinceItIsTooSmall() {
+    assertFalse(validator.isValidBeautifulNumber("1"));
+  }
+}
\ No newline at end of file

From 41b7f230d010ba8b081d2d8de963e13fba91f231 Mon Sep 17 00:00:00 2001
From: jaebradley <jae.b.bradley@gmail.com>
Date: Wed, 19 Jul 2017 15:18:38 -0400
Subject: [PATCH 2/2] add codereview markdown

---
 codereview/beautifulNumberValidator.md | 42 ++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 codereview/beautifulNumberValidator.md

diff --git a/codereview/beautifulNumberValidator.md b/codereview/beautifulNumberValidator.md
new file mode 100644
index 0000000..9d371d8
--- /dev/null
+++ b/codereview/beautifulNumberValidator.md
@@ -0,0 +1,42 @@
+## Problem
+Adapted from [this HackerRank problem](https://www.hackerrank.com/challenges/separate-the-numbers/problem).
+
+[![Beautiful Number Description][1]][1]
+
+Instead of printing `YES` or `NO`, I just wanted to return a `boolean`.
+
+## Implementation
+
+<! -- language: lang-java -->
+
+    public class BeautifulNumberValidator {
+      public static boolean isValidBeautifulNumber(String s) {
+        if (s.length() < 2) {
+          return false;
+        }
+
+        for (int substringSize = 1; substringSize <= s.length() / 2; substringSize++) {
+          long value = Long.parseLong(s.substring(0, substringSize));
+
+          if (value == 0) {
+            break;
+          }
+
+          StringBuilder sb = new StringBuilder();
+          sb.append(value);
+
+          while (sb.length() < s.length() && sb.toString().equals(s.substring(0, sb.length()))) {
+            sb.append(++value);
+          }
+
+          if (sb.toString().equals(s)) {
+            return true;
+          }
+        }
+
+        return false;
+      }
+    }
+
+
+  [1]: https://i.stack.imgur.com/p8HI7.png
\ No newline at end of file