Add Python solution to challenge 15

6 files changed, 119 insertions, 28 deletions

diff --git a/challenge-015/paulo-custodio/Makefile b/challenge-015/paulo-custodio/Makefile
new file mode 100644
index 0000000000..c3c762d746
--- /dev/null
+++ b/challenge-015/paulo-custodio/Makefile
@@ -0,0 +1,2 @@
+all:
+	perl ../../challenge-001/paulo-custodio/test.pl
diff --git a/challenge-015/paulo-custodio/python/ch-1.py b/challenge-015/paulo-custodio/python/ch-1.py
new file mode 100644
index 0000000000..d1e6cfc85c
--- /dev/null
+++ b/challenge-015/paulo-custodio/python/ch-1.py
@@ -0,0 +1,55 @@
+#!/usr/bin/python3
+
+# Challenge 015
+#
+# Task #1
+# Write a script to generate first 10 strong and weak prime numbers.
+#
+#   For example, the nth prime number is represented by p(n).
+#
+#   p(1) = 2
+#   p(2) = 3
+#   p(3) = 5
+#   p(4) = 7
+#   p(5) = 11
+#
+#   Strong Prime number p(n) when p(n) > [ p(n-1) + p(n+1) ] / 2
+#   Weak   Prime number p(n) when p(n) < [ p(n-1) + p(n+1) ] / 2
+
+import sys
+from primePy import primes
+
+def next_prime(n):
+    if n <= 1:
+        return 2
+    else:
+        n += 1
+        while not primes.check(n):
+            n += 1
+        return n
+
+def prime_iter(strong):
+    last = [1,2,3]       # 1 + first two primes; 1 is discarded on first iteration
+    while True:
+        # get next prime, drop oldest
+        last.pop(0)
+        last.append(next_prime(last[-1]))
+
+        avg = (last[-3]+last[-1])/2
+        if strong:
+            if last[-2] > avg:
+                yield last[-2]
+        else:
+            if last[-2] < avg:
+                yield last[-2]
+
+def primes_list(num, strong):
+    result = []
+    for p in prime_iter(strong):
+        result.append(p)
+        if len(result) >= num:
+            return result
+
+num = int(sys.argv[1])
+print("Strong Prime: "+", ".join([str(x) for x in primes_list(num, True)]))
+print("Weak Prime:   "+", ".join([str(x) for x in primes_list(num, False)]))
diff --git a/challenge-015/paulo-custodio/python/ch-2.py b/challenge-015/paulo-custodio/python/ch-2.py
new file mode 100644
index 0000000000..3d2de230da
--- /dev/null
+++ b/challenge-015/paulo-custodio/python/ch-2.py
@@ -0,0 +1,38 @@
+#!/usr/bin/python3
+
+# Challenge 015
+#
+# Task #2
+# Write a script to implement Vigenere cipher. The script should be able encode
+# and decode. Checkout wiki page for more information.
+
+import sys
+
+def text_codes(text):
+    codes = []
+    for c in text.upper():
+        if c.isalpha():
+            codes.append(ord(c)-ord('A'))
+    return codes
+
+def codes_text(codes):
+    return "".join([chr(ord('A')+x) for x in codes])
+
+def vigenere(plain, key, encode):
+    plain = text_codes(plain)
+    key = text_codes(key)
+    ikey = 0
+    cipher = []
+    for c in plain:
+        if encode:
+            cipher.append((c + key[ikey])%26)
+        else:
+            cipher.append((c - key[ikey] + 26)%26)
+        ikey = (ikey+1) % len(key)
+    return codes_text(cipher)
+
+encode = True if sys.argv[1]=="encode" else False
+key = sys.argv[2]
+text = " ".join(sys.argv[3:])
+
+print(vigenere(text, key, encode))
diff --git a/challenge-015/paulo-custodio/t/test-1.yaml b/challenge-015/paulo-custodio/t/test-1.yaml
new file mode 100644
index 0000000000..2d9c887792
--- /dev/null
+++ b/challenge-015/paulo-custodio/t/test-1.yaml
@@ -0,0 +1,14 @@
+- setup:
+  cleanup:
+  args:     10
+  input:
+  output:   |
+            Strong Prime: 11, 17, 29, 37, 41, 59, 67, 71, 79, 97
+            Weak Prime:   3, 7, 13, 19, 23, 31, 43, 47, 61, 73
+- setup:
+  cleanup:
+  args:     47
+  input:
+  output:   |
+            Strong Prime: 11, 17, 29, 37, 41, 59, 67, 71, 79, 97, 101, 107, 127, 137, 149, 163, 179, 191, 197, 223, 227, 239, 251, 269, 277, 281, 307, 311, 331, 347, 367, 379, 397, 419, 431, 439, 457, 461, 479, 487, 499, 521, 541, 557, 569, 587, 599
+            Weak Prime:   3, 7, 13, 19, 23, 31, 43, 47, 61, 73, 83, 89, 103, 109, 113, 131, 139, 151, 167, 181, 193, 199, 229, 233, 241, 271, 283, 293, 313, 317, 337, 349, 353, 359, 383, 389, 401, 409, 421, 433, 443, 449, 463, 467, 491, 503, 509
diff --git a/challenge-015/paulo-custodio/t/test-2.yaml b/challenge-015/paulo-custodio/t/test-2.yaml
new file mode 100644
index 0000000000..4e5149b8a9
--- /dev/null
+++ b/challenge-015/paulo-custodio/t/test-2.yaml
@@ -0,0 +1,10 @@
+- setup:
+  cleanup:
+  args:     encode LEMON ATTACKATDAWN
+  input:
+  output:   LXFOPVEFRNHR
+- setup:
+  cleanup:
+  args:     decode LEMON LXFOPVEFRNHR
+  input:
+  output:   ATTACKATDAWN
diff --git a/challenge-015/paulo-custodio/test.pl b/challenge-015/paulo-custodio/test.pl
deleted file mode 100644
index 6959f9ba6e..0000000000
--- a/challenge-015/paulo-custodio/test.pl
+++ /dev/null
@@ -1,28 +0,0 @@
-#!/usr/bin/perl
-
-use Modern::Perl;
-use Test::More;
-
-is capture("perl perl/ch-1.pl"), <<END;
-Strong Prime: 11, 17, 29, 37, 41, 59, 67, 71, 79, 97
-Weak Prime:   3, 7, 13, 19, 23, 31, 43, 47, 61, 73
-END
-
-is capture("perl perl/ch-1.pl 47"), <<END;
-Strong Prime: 11, 17, 29, 37, 41, 59, 67, 71, 79, 97, 101, 107, 127, 137, 149, 163, 179, 191, 197, 223, 227, 239, 251, 269, 277, 281, 307, 311, 331, 347, 367, 379, 397, 419, 431, 439, 457, 461, 479, 487, 499, 521, 541, 557, 569, 587, 599
-Weak Prime:   3, 7, 13, 19, 23, 31, 43, 47, 61, 73, 83, 89, 103, 109, 113, 131, 139, 151, 167, 181, 193, 199, 229, 233, 241, 271, 283, 293, 313, 317, 337, 349, 353, 359, 383, 389, 401, 409, 421, 433, 443, 449, 463, 467, 491, 503, 509
-END
-
-
-is capture("perl perl/ch-2.pl encode LEMON ATTACKATDAWN"), "LXFOPVEFRNHR\n";
-is capture("perl perl/ch-2.pl decode LEMON LXFOPVEFRNHR"), "ATTACKATDAWN\n";
-
-
-done_testing;
-
-sub capture {
-    my($cmd) = @_;
-    my $out = `$cmd`;
-    $out =~ s/[ \t\v\f\r]*\n/\n/g;
-    return $out;
-}