Simon's solution to challenge 198

6 files changed, 134 insertions, 2 deletions

diff --git a/challenge-198/sgreen/README.md b/challenge-198/sgreen/README.md
index e88b63ed82..5d5a8941b6 100644
--- a/challenge-198/sgreen/README.md
+++ b/challenge-198/sgreen/README.md
@@ -1,3 +1,3 @@
-# The Weekly Challenge 197
+# The Weekly Challenge 198
 
-Blog [Sorting Lists](https://dev.to/simongreennet/sorting-lists-35fh)
+[Blog](https://dev.to/simongreennet/weekly-challenge-198-2jbl)
diff --git a/challenge-198/sgreen/blog.txt b/challenge-198/sgreen/blog.txt
new file mode 100644
index 0000000000..130b262845
--- /dev/null
+++ b/challenge-198/sgreen/blog.txt
@@ -0,0 +1 @@
+https://dev.to/simongreennet/weekly-challenge-198-2jbl
\ No newline at end of file
diff --git a/challenge-198/sgreen/perl/ch-1.pl b/challenge-198/sgreen/perl/ch-1.pl
new file mode 100644
index 0000000000..616806f34b
--- /dev/null
+++ b/challenge-198/sgreen/perl/ch-1.pl
@@ -0,0 +1,33 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+use experimental 'signatures';
+
+sub main (@list) {
+    my $gap   = 0;    # The maximum gap
+    my $count = 0;    # Number of occurrences
+
+    # Sort the list
+    @list = sort { $a <=> $b } @list;
+
+    # Iterate through the list
+    foreach my $i ( 0 .. $#list - 1 ) {
+        my $diff = $list[ $i + 1 ] - $list[$i];
+        if ( $diff > $gap ) {
+            # We have a new maximum, reset the count
+            $gap   = $diff;
+            $count = 1;
+        }
+        elsif ( $diff == $gap ) {
+            # Add to the count
+            $count++;
+        }
+    }
+
+    # Display the result
+    say $count;
+}
+
+main(@ARGV);
\ No newline at end of file
diff --git a/challenge-198/sgreen/perl/ch-2.pl b/challenge-198/sgreen/perl/ch-2.pl
new file mode 100644
index 0000000000..55443b9098
--- /dev/null
+++ b/challenge-198/sgreen/perl/ch-2.pl
@@ -0,0 +1,33 @@
+#!/usr/bin/env perl
+
+use strict;
+use warnings;
+use feature 'say';
+use experimental 'signatures';
+
+sub is_prime ($number) {
+    # Return true or false if the number is a prime
+    return if $number < 2;
+
+    foreach my $i ( 2 .. sqrt($number) ) {
+        return if $number % $i == 0;
+    }
+
+    # It's a prime
+    return 1;
+}
+
+sub main ($n) {
+    # Count the number of primes
+    my $count = 0;
+
+    # Iterate from 1 to n
+    foreach my $i ( 1 .. $n - 1 ) {
+        # If it is a prime, add to count
+        ++$count if is_prime($i);
+    }
+
+    say $count;
+}
+
+main( $ARGV[0] );
\ No newline at end of file
diff --git a/challenge-198/sgreen/python/ch-1.py b/challenge-198/sgreen/python/ch-1.py
new file mode 100755
index 0000000000..c1981be24c
--- /dev/null
+++ b/challenge-198/sgreen/python/ch-1.py
@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+
+import sys
+
+
+def main(n):
+    gap = 0     # The maximum gap
+    count = 0   # Number of occurrences
+
+    # Sort the list
+    n = sorted(n)
+
+    # Iterate through the list
+    for i in range(len(n)-1):
+        diff = n[i+1] - n[i]
+        if diff > gap:
+            # We have a new maximum, reset the count
+            gap = diff
+            count = 1
+        elif diff == gap:
+            # Add to the count
+            count += 1
+
+    # Display the result
+    print(count)
+
+
+if __name__ == '__main__':
+    # Turn the strings into integers
+    n = [int(i) for i in sys.argv[1:]]
+    main(n)
diff --git a/challenge-198/sgreen/python/ch-2.py b/challenge-198/sgreen/python/ch-2.py
new file mode 100755
index 0000000000..1846353a16
--- /dev/null
+++ b/challenge-198/sgreen/python/ch-2.py
@@ -0,0 +1,34 @@
+#!/usr/bin/env python3
+
+import math
+import sys
+
+
+def is_prime(number):
+    '''Return true or false if the number is a prime'''
+    if number < 2:
+        return False
+
+    for i in range(2, int(math.sqrt(number)) + 1):
+        if number % i == 0:
+            return False
+
+    # It's a prime
+    return True
+
+
+def main(n):
+    # Count the number of primes
+    count = 0
+
+    # Iterate from 1 to n-1
+    for i in range(1, n):
+        # If it is a prime, add to count
+        if is_prime(i):
+            count += 1
+
+    print(count)
+
+
+if __name__ == '__main__':
+    main(int(sys.argv[1]))