From 006b9d263db368ec182003e98899fc0b0fbd4d3e Mon Sep 17 00:00:00 2001
From: Mohammad S Anwar <mohammad.anwar@yahoo.com>
Date: Sat, 16 Jul 2022 23:54:29 +0100
Subject: - Added Java solutions to the week 173.

---
 .../java/theweeklychallenge/EstheticNumber.java    | 50 +++++++++++++++++
 .../java/theweeklychallenge/SylvesterSequence.java | 65 ++++++++++++++++++++++
 2 files changed, 115 insertions(+)
 create mode 100644 challenge-173/mohammad-anwar/java/theweeklychallenge/EstheticNumber.java
 create mode 100644 challenge-173/mohammad-anwar/java/theweeklychallenge/SylvesterSequence.java

diff --git a/challenge-173/mohammad-anwar/java/theweeklychallenge/EstheticNumber.java b/challenge-173/mohammad-anwar/java/theweeklychallenge/EstheticNumber.java
new file mode 100644
index 0000000000..bb98b29fd9
--- /dev/null
+++ b/challenge-173/mohammad-anwar/java/theweeklychallenge/EstheticNumber.java
@@ -0,0 +1,50 @@
+package theweeklychallenge;
+
+/*
+
+Week 173:
+
+    https://theweeklychallenge.org/blog/perl-weekly-challenge-173
+
+Task #1: Esthetic Number
+
+    You are given a positive integer, $n.
+
+    Write a script to find out if the given number is Esthetic Number.
+
+Compile and Run:
+
+    mohammad-anwar/java$ javac theweeklychallenge/EstheticNumber.java
+    mohammad-anwar/java$ java  theweeklychallenge.EstheticNumber
+
+*/
+
+import java.lang.Math;
+import junit.framework.TestCase;
+import static junit.framework.Assert.*;
+
+public class EstheticNumber extends TestCase {
+
+    public static void main(String[] args) {
+        junit.textui.TestRunner.run(
+            theweeklychallenge.EstheticNumber.class);
+    }
+
+    public void testEstheticNumber() {
+        assertTrue(isEstheticNumber(5456));
+        assertFalse(isEstheticNumber(120));
+    }
+
+    public static boolean isEstheticNumber(int n) {
+        String s = Integer.toString(n);
+        int i = 1;
+        while (i < s.length()) {
+            if (Math.abs((int)(s.charAt(i-1)) - (int)(s.charAt(i))) != 1) {
+                return false;
+            }
+            i++;
+        }
+
+        return true;
+    }
+}
diff --git a/challenge-173/mohammad-anwar/java/theweeklychallenge/SylvesterSequence.java b/challenge-173/mohammad-anwar/java/theweeklychallenge/SylvesterSequence.java
new file mode 100644
index 0000000000..8f4400e4e0
--- /dev/null
+++ b/challenge-173/mohammad-anwar/java/theweeklychallenge/SylvesterSequence.java
@@ -0,0 +1,65 @@
+package theweeklychallenge;
+
+/*
+
+Week 173:
+
+    https://theweeklychallenge.org/blog/perl-weekly-challenge-173
+
+Task #2: Sylvester’s sequence
+
+    Write a script to generate first 10 members of Sylvester's sequence.
+
+Compile and Run:
+
+    mohammad-anwar/java$ javac theweeklychallenge/SylvesterSequence.java
+    mohammad-anwar/java$ java  theweeklychallenge.SylvesterSequence
+
+*/
+
+import java.lang.Math;
+import java.util.Arrays;
+import java.util.ArrayList;
+import java.math.BigInteger;
+import junit.framework.TestCase;
+import static junit.framework.Assert.*;
+
+public class SylvesterSequence extends TestCase {
+
+    public static void main(String[] args) {
+        junit.textui.TestRunner.run(
+            theweeklychallenge.SylvesterSequence.class);
+    }
+
+    public void testSylvesterSequence() {
+        BigInteger exp[] = {
+             BigInteger.valueOf(2)
+            ,BigInteger.valueOf(3)
+            ,BigInteger.valueOf(7)
+            ,BigInteger.valueOf(43)
+            ,BigInteger.valueOf(1807)
+            ,BigInteger.valueOf(3263443)
+            ,new BigInteger("10650056950807")
+            ,new BigInteger("113423713055421844361000443")
+            ,new BigInteger("12864938683278671740537145998360961546653259485195807")
+            ,new BigInteger("165506647324519964198468195444439180017513152706377497841851388766535868639572406808911988131737645185443")
+        };
+
+        BigInteger got[] = sylvesterSequence(10);
+
+        assertTrue(Arrays.equals(exp, got));
+    }
+
+    public static BigInteger[] sylvesterSequence(int n) {
+        ArrayList<BigInteger> _ss = new ArrayList<BigInteger>();
+        _ss.add(BigInteger.valueOf(2));
+        int i = 1;
+        while (i++ <= n - 1) {
+            BigInteger m  = _ss.get(_ss.size() - 1);
+            _ss.add((m.multiply(m.subtract(BigInteger.valueOf(1)))).add(BigInteger.valueOf(1)));
+        }
+
+        BigInteger[] ss = new BigInteger[_ss.size()];
+        return _ss.toArray(ss);
+    }
+}
-- 
cgit