Merge pull request #3199 from E7-87-83/master

2 Perl Scripts, and a Java solution for task 2, a blogpost

6 files changed, 388 insertions, 0 deletions

diff --git a/challenge-094/cheok-yin-fung/blog.txt b/challenge-094/cheok-yin-fung/blog.txt
new file mode 100644
index 0000000000..01dc4ccbb4
--- /dev/null
+++ b/challenge-094/cheok-yin-fung/blog.txt
@@ -0,0 +1 @@
+http://blogs.perl.org/users/c_y_fung/2021/01/cys-take-on-pwc094.html
diff --git a/challenge-094/cheok-yin-fung/java/BT2LL.java b/challenge-094/cheok-yin-fung/java/BT2LL.java
new file mode 100644
index 0000000000..de1470ccf2
--- /dev/null
+++ b/challenge-094/cheok-yin-fung/java/BT2LL.java
@@ -0,0 +1,62 @@
+// The Weekly Challenge #094 Task 2
+// ref:*  hhttps://www.includehelp.com/data-structure-tutorial/
+//        preorder-traversal-in-binary-tree-iteratively-without-recursion.aspx
+//     *  https://www.journaldev.com/13401/java-stack
+
+import java.util.Scanner;
+import java.util.Stack;
+
+public class BT2LL
+{
+    public static LinkedList traversal (BinaryTree t)
+    {
+        
+        LinkedList.LLNode h = new LinkedList.LLNode(0);
+        LinkedList target = new LinkedList();
+        target.setHead(h);
+
+        Stack<BinaryTree.BTNode> ttStack = new Stack<>();
+        ttStack.push(t.root);
+
+        LinkedList.LLNode pretemp = h;
+        BinaryTree.BTNode cur = null;
+        LinkedList.LLNode temp = null;
+
+        while (!ttStack.isEmpty()) {
+            cur = ttStack.pop();
+            temp = new LinkedList.LLNode(cur.value);
+            LinkedList.NewLink(pretemp, temp);
+            pretemp = temp;
+            if (cur.rightChild != null) {
+                ttStack.push(cur.rightChild);
+            }
+            if (cur.leftChild != null) {
+                ttStack.push(cur.leftChild);
+            }
+        }
+        
+        return target;
+    }
+
+    public static void main(String[] args)
+    {
+        BinaryTree ninefour = new BinaryTree();
+        BinaryTree.BTNode first = new BinaryTree.BTNode(1);
+        BinaryTree.BTNode second = new BinaryTree.BTNode(2);
+        BinaryTree.BTNode third = new BinaryTree.BTNode(3);
+        BinaryTree.BTNode fourth = new BinaryTree.BTNode(4);
+        BinaryTree.BTNode fifth = new BinaryTree.BTNode(5);
+        BinaryTree.BTNode sixth = new BinaryTree.BTNode(6);
+        BinaryTree.BTNode seventh = new BinaryTree.BTNode(7);
+        BinaryTree.setLeftChild(first, second);
+        BinaryTree.setRightChild(first, third);
+        BinaryTree.setLeftChild(second, fourth);
+        BinaryTree.setRightChild(second, fifth);
+        BinaryTree.setLeftChild(fifth, sixth);
+        BinaryTree.setRightChild(fifth, seventh);
+
+        ninefour.setRoot(first);
+        LinkedList ans = traversal(ninefour);
+        LinkedList.printLL_without_h(ans);
+    }
+}
diff --git a/challenge-094/cheok-yin-fung/java/BinaryTree.java b/challenge-094/cheok-yin-fung/java/BinaryTree.java
new file mode 100644
index 0000000000..5bc31f3c8c
--- /dev/null
+++ b/challenge-094/cheok-yin-fung/java/BinaryTree.java
@@ -0,0 +1,46 @@
+// The Weekly Challenge #094
+// ref: https://codereview.stackexchange.com/
+//      questions/37944/constructing-a-binary-tree-in-java
+
+
+import java.util.Scanner;
+
+public class BinaryTree
+{
+    public static BTNode root;
+
+    public static class BTNode
+    {
+        BTNode leftChild;
+        BTNode rightChild;
+        int value;
+
+        BTNode(int d)
+        {
+            value = d;
+            leftChild = null;
+            rightChild = null;
+        }
+    }
+
+    public static void setLeftChild (BTNode p, BTNode kid)
+    {
+        p.leftChild = kid;
+    }
+    public static void setRightChild (BTNode p, BTNode kid)
+    {
+        p.rightChild = kid;
+    }
+
+    public static void setRoot (BTNode n)
+    {
+        root = n;
+    }
+
+    public int getValue(BTNode n) 
+    {
+        return n.value;
+    }
+
+
+}
diff --git a/challenge-094/cheok-yin-fung/java/LinkedList.java b/challenge-094/cheok-yin-fung/java/LinkedList.java
new file mode 100644
index 0000000000..0b58aaef6f
--- /dev/null
+++ b/challenge-094/cheok-yin-fung/java/LinkedList.java
@@ -0,0 +1,58 @@
+// The Weekly Challenge #094
+// ref: https://www.geeksforgeeks.org/
+//      implementing-a-linked-list-in-java-using-class/
+import java.util.Scanner;
+
+public class LinkedList 
+{
+    static LLNode head;
+
+    static class LLNode
+    {
+        LLNode next;
+        int value;
+
+        LLNode(int d)
+        {
+            value = d;
+            next = null;
+        }
+    }
+
+    public static void NewLink ( LLNode front, LLNode back)
+    {
+        front.next = back;
+    }
+
+    public static void printLL(LinkedList list)
+    {
+        LLNode node = list.head;
+        while (node.next != null) {
+            System.out.print(node.value + " -> ");
+            node = node.next;
+        }
+        System.out.println(node.value);       //final value
+    }
+
+    public static void printLL_without_h(LinkedList list)
+    {
+        LLNode node = list.head;
+        while (node.next != null) {
+            node = node.next;
+            System.out.print(node.value + " -> ");
+        }
+        System.out.println("end");
+    }
+
+    public static void setHead (LLNode n)
+    {
+        head = n;
+    }
+
+    public int getValue(LLNode n) 
+    {
+        return n.value;
+    }
+
+
+}
diff --git a/challenge-094/cheok-yin-fung/perl/ch-1.pl b/challenge-094/cheok-yin-fung/perl/ch-1.pl
new file mode 100644
index 0000000000..6bc9e76905
--- /dev/null
+++ b/challenge-094/cheok-yin-fung/perl/ch-1.pl
@@ -0,0 +1,68 @@
+#!/usr/bin/perl
+# The Weekly Challenge 094
+# Task 1 Group Anagrams
+# Usage: ch-1.pl [@S]
+use strict;
+use warnings;
+use utf8;
+use open ':std', ':encoding(UTF-8)';
+# unicode info:
+# 0. http://blogs.perl.org/users/c_y_fung/
+#    2021/01/from-a-reflection-on-the-weekly-challenge-092-task-1.html
+# 1. https://stackoverflow.com/questions/15210532/use-of-use-
+#    utf8-gives-me-wide-character-in-print
+# 2. https://www.reddit.com/r/perl/comments/koahhf/
+#    from_a_reflection_on_the_weekly_challenge_092/
+
+
+my %hash_num;
+
+sub collect_alphabets {
+    my @words = @_;
+    my @alphabets = split //, join("" , @words); 
+    my $i = 0;
+    for (@alphabets) {
+        if (!exists $hash_num{$_}) { 
+            $hash_num{$_} = $i++;
+        }
+    }
+}
+
+sub learn_atoms {
+    my $word = $_[0];
+    my @alphabets = split //, $word;
+    my @coord = map {$hash_num{$_}} @alphabets;
+    @coord = sort @coord;
+    return join ",", @coord;
+}
+
+sub compare_two_words {       # a testing function
+    return learn_atoms($_[0]) eq learn_atoms($_[1]) ? 1 : 0; 
+}
+
+collect_alphabets(@ARGV);
+
+my %hash_compounds;
+my @arr;
+my $k = 0;
+
+for my $w (@ARGV) {
+    my $l = learn_atoms($w);
+    if (!exists $hash_compounds{$l}) {
+        $hash_compounds{$l} = $k; 
+        $arr[$k] = [$w];
+        $k++;
+    } 
+    else {
+        push @{$arr[ $hash_compounds{$l} ]}, $w;
+    }
+}
+
+$k--;
+
+for my $j (0..$k) {
+    print "(\"";
+    print join "\",\"", @{$arr[$j]};
+    print "\")\n"; 
+}
+
diff --git a/challenge-094/cheok-yin-fung/perl/ch-2.pl b/challenge-094/cheok-yin-fung/perl/ch-2.pl
new file mode 100644
index 0000000000..bf86a5f015
--- /dev/null
+++ b/challenge-094/cheok-yin-fung/perl/ch-2.pl
@@ -0,0 +1,153 @@
+#!/usr/bin/perl
+# The Weekly Challenge 094
+# Task 2: Binary Tree to Linked List
+use strict;
+use warnings;
+use Data::Dumper;
+
+{
+use strict;
+package SLL::Node;
+
+sub new {
+    my ($class) = @_;
+    bless {
+        _value => $_[1],
+        _nextnode => $_[2],
+    }, $class; 
+}
+
+
+sub value { $_[0]->{_value} }
+
+sub nextnode { $_[0]->{_nextnode} }
+
+sub set_nextnode { $_[0]->{_nextnode} = $_[1]; }
+
+sub print_linked_list {
+    my $node = $_[0];
+    while (defined $node->nextnode) {
+        print $node->value, " -> ";
+        $node = $node->nextnode;
+    }
+    print $node->value; #final value
+    print "\n";
+}
+
+
+} # END of package SLL::Node
+
+
+{
+use strict;
+package BinaryTreeNode;
+
+our @ISA = qw/ SLL::Node /;
+
+sub new {
+    my ($class) = @_;
+    bless {
+        _value => $_[1],
+        _leftchild => $_[2],
+        _rightchild => $_[3],
+    }, $class;
+}
+
+sub value { $_[0]->{_value} }
+
+sub leftchild { $_[0]->{_leftchild} }
+
+sub rightchild { $_[0]->{_rightchild} }
+
+sub create_tree_from_list {
+    my ($class,@arr) = @_;
+    my $lastleaf = $#arr;
+    my @tree;
+
+    for my $k (reverse 0..$lastleaf) {
+        if (defined($arr[$k])) {
+            if (defined($arr[$k*2+1]) and defined($arr[$k*2+2])) {
+                $tree[$k] = BinaryTreeNode->new(
+                  $arr[$k], \$tree[$k*2+1], \$tree[$k*2+2]) 
+            }
+            if (defined($arr[$k*2+1]) and !defined($arr[$k*2+2])) {
+                $tree[$k] = BinaryTreeNode->new(
+                  $arr[$k], \$tree[$k*2+1], undef) 
+            }
+            if (!defined($arr[$k*2+1]) and defined($arr[$k*2+2])) {
+                $tree[$k] = BinaryTreeNode->new(
+                  $arr[$k], undef, \$tree[$k*2+2]) 
+            }
+            if (!defined($arr[$k*2+1]) and !defined($arr[$k*2+2])) {
+                $tree[$k] = BinaryTreeNode->new(
+                  $arr[$k], undef, undef) 
+            }
+        }
+             
+    }
+
+    return $class, $tree[0];  #return tree root
+}
+
+my @tt_stack = ();
+
+sub to_llnode {
+    return SLL::Node->new(shift, undef);
+}
+
+sub tree_travel {
+    my $self = shift;
+    my $t = shift;
+    my $baby = to_llnode($t->value);
+    my $preserve = \$baby;
+   
+    if (defined $t->leftchild) {
+        push @tt_stack, $t->rightchild if defined $t->rightchild ;
+        $baby->set_nextnode(tree_travel($self,${$t->leftchild}));
+    } elsif (defined $t->rightchild) {
+        $baby->set_nextnode(tree_travel($self,${$t->rightchild}));
+    
+    } elsif (scalar @tt_stack != 0) {
+        my $n = pop @tt_stack;
+        $baby->set_nextnode(tree_travel($self,${$n}));
+    }
+
+    return $$preserve;
+}
+
+
+}  #END of package BinaryTreeNode
+
+
+
+my $root = BinaryTreeNode->
+        create_tree_from_list(1,2,3,4,5, undef, 
+                              undef, undef, undef,6,7); # Example
+
+my $rootnode = BinaryTreeNode->tree_travel($root);
+
+print "Example\n";
+$rootnode->print_linked_list;
+
+print "\n";
+
+
+
+
+print "A Test Case\n";
+=pod
+          1
+        |---|
+       /     \
+      2       3
+     /  \    /  \ 
+    4    5  6    7
+   / \   /\
+  8  9  10 11
+=cut
+
+my $treeroot2 = BinaryTreeNode->
+        create_tree_from_list(1, 2, 3, 4, 5, 6,7,8,9,10,11);  # test case
+
+my $rootnode2 = BinaryTreeNode->tree_travel($treeroot2);
+$rootnode2->print_linked_list;