Add Python solution to challenge 170-task 2

2 files changed, 81 insertions, 1 deletions

diff --git a/challenge-170/paulo-custodio/perl/ch-2.pl b/challenge-170/paulo-custodio/perl/ch-2.pl
index aa101be3a9..92e0d5b3c2 100644
--- a/challenge-170/paulo-custodio/perl/ch-2.pl
+++ b/challenge-170/paulo-custodio/perl/ch-2.pl
@@ -61,7 +61,7 @@ sub parse_input {
 sub kronecker_product {
     my($a, $b) = @_;
     my $wa = @{$a->[0]}; my $ha = @$a;
-    my $wb = @{$b->[0]}; my $hb = @$a;
+    my $wb = @{$b->[0]}; my $hb = @$b;
     my @prod;
     for my $ar (0..$ha-1) {
         for my $ac (0..$wa-1) {
diff --git a/challenge-170/paulo-custodio/python/ch-2.py b/challenge-170/paulo-custodio/python/ch-2.py
new file mode 100644
index 0000000000..ed5be6a669
--- /dev/null
+++ b/challenge-170/paulo-custodio/python/ch-2.py
@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+
+# Challenge 170
+#
+# Task 2: Kronecker Product
+# Submitted by: Mohammad S Anwar
+#
+# You are given 2 matrices.
+#
+# Write a script to implement Kronecker Product on the given 2 matrices.
+#
+# For more information, please refer wikipedia page.
+#
+# For example,
+#
+# A = [ 1 2 ]
+#     [ 3 4 ]
+#
+# B = [ 5 6 ]
+#     [ 7 8 ]
+#
+# A x B = [ 1 x [ 5 6 ]   2 x [ 5 6 ] ]
+#         [     [ 7 8 ]       [ 7 8 ] ]
+#         [ 3 x [ 5 6 ]   4 x [ 5 6 ] ]
+#         [     [ 7 8 ]       [ 7 8 ] ]
+#
+#       = [ 1x5 1x6 2x5 2x6 ]
+#         [ 1x7 1x8 2x7 2x8 ]
+#         [ 3x5 3x6 4x5 4x6 ]
+#         [ 3x7 3x8 4x7 4x8 ]
+#
+#       = [  5  6 10 12 ]
+#         [  7  8 14 16 ]
+#         [ 15 18 20 24 ]
+#         [ 21 24 28 32 ]
+
+import sys
+import re
+
+def parse_matrix(line):
+    mx = []
+    while re.match(r'^\s*$', line):
+        line = sys.stdin.readline()
+    line, count = re.subn(r'^\s*\w+\s*=\s*', '', line)
+    if count == 0:
+        raise ValueError("assignment expected")
+    while found := re.match(r'^\s*\[([\d\s]+)\]\s*$', line):
+        row = [int(x) for x in found.group(1).split()]
+        mx.append(row)
+        line = sys.stdin.readline()
+    return mx, line
+
+def parse_input():
+    line = sys.stdin.readline()
+    a, line = parse_matrix(line)
+    b, line = parse_matrix(line)
+    return a, b
+
+def print_matrix(mx):
+    for row in mx:
+        print("[ "+ " ".join([str(x) for x in row]) +" ]")
+
+def kronecker_product(a, b):
+    wa = len(a[0])
+    ha = len(a)
+    wb = len(b[0])
+    hb = len(b)
+    prod = [[0 for _ in range(wa*wb)] for _ in range(ha*hb)]
+    for ar in range(ha):
+        for ac in range(wa):
+            for br in range(hb):
+                for bc in range(wb):
+                    tr = ar*hb + br
+                    tc = ac*wb + bc
+                    prod[tr][tc] = a[ar][ac] * b[br][bc]
+    return prod
+
+a, b = parse_input()
+p = kronecker_product(a, b)
+print_matrix(p)