1 files changed, 49 insertions, 0 deletions
diff --git a/challenge-248/packy-anderson/python/ch-2.py b/challenge-248/packy-anderson/python/ch-2.py
new file mode 100755
index 0000000000..a31b91af1a
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+++ b/challenge-248/packy-anderson/python/ch-2.py
@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+
+def submatrixSum(a):
+    # subtract 1 because we're 0-indexed
+    M = len(a) - 1    # rows
+    N = len(a[0]) - 1 # columns
+    # we are ASSUMING the matrix is consistent with
+    # each row having the same number of columns
+    b = []
+    for i in range(M):
+        row = []
+        for k in range(N):
+            row.append( a[i  ][k] + a[i  ][k+1] +
+                        a[i+1][k] + a[i+1][k+1] )
+        b.append(row)
+    return b
+
+def formatMatrix(matrix, indent=13):
+    output = []
+    for row in matrix:
+        output_row = ' ' * indent + '  ['
+        output_row += ', '.join(map(lambda i: str(i), row))
+        output_row += ']'
+        output.append(output_row)
+
+    return(
+        "[\n" + ",\n".join(output) + "\n" +
+        ' ' * indent + ']'
+    )
+
+def solution(a):
+    print(f'Input:  $a = {formatMatrix(a)}')
+    b = submatrixSum(a)
+    print(f'Output: $b = {formatMatrix(b)}')
+
+print('Example 1:')
+solution([
+            [1,  2,  3,  4],
+            [5,  6,  7,  8],
+            [9, 10, 11, 12]
+         ])
+
+print('\nExample 2:')
+solution([
+            [1, 0, 0, 0],
+            [0, 1, 0, 0],
+            [0, 0, 1, 0],
+            [0, 0, 0, 1]
+         ])