Added a similar Python program for comparison purposes, along with a …

…sample complex board.

.gitignore

@@ -10,3 +10,105 @@
 
 # Output of the go coverage tool, specifically when used with LiteIDE
 *.out
+
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+.hypothesis/
+.pytest_cache/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# pyenv
+.python-version
+
+# celery beat schedule file
+celerybeat-schedule
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/

README.md

@@ -1,2 +1,3 @@
 # rullo
 A solver for the Rullo game.
+I've included Go and Python versions so you can compare ease, performance, resource consumption, etc.

board.py

@@ -0,0 +1,7 @@
+# sample board
+board = [
+    [1, 2, 3, 4, 6],
+    [5, 6, 7, 8,13],
+    [9, 10, 11, 12, 31],
+    [15, 12, 3, 20]
+]

complex.py

@@ -0,0 +1,11 @@
+board = [
+	[2, 2, 3, 4, 3, 4, 4, 3, 17],
+	[4, 2, 3, 4, 3, 3, 4, 4, 16],
+	[2, 2, 3, 2, 4, 4, 4, 4, 12],
+	[2, 4, 3, 3, 4, 4, 2, 4, 14],
+	[2, 4, 4, 2, 2, 4, 4, 2, 20],
+	[2, 4, 2, 4, 3, 3, 2, 2, 20],
+	[2, 2, 2, 2, 2, 4, 3, 2, 17],
+	[4, 3, 2, 3, 4, 4, 4, 2, 22],
+	[16, 19, 19, 18, 18, 22, 7, 19]
+]

complex.txt

@@ -0,0 +1,11 @@
+# 115 solutions
+8 8
+2 2 3 4 3 4 4 3 17
+4 2 3 4 3 3 4 4 16
+2 2 3 2 4 4 4 4 12
+2 4 3 3 4 4 2 4 14
+2 4 4 2 2 4 4 2 20
+2 4 2 4 3 3 2 2 20
+2 2 2 2 2 4 3 2 17
+4 3 2 3 4 4 4 2 22
+16 19 19 18 18 22 7 19

rullo.py

@@ -0,0 +1,56 @@
+#! /usr/bin/python3
+
+# rullo.py
+
+# A tool to solve a Rullo board.
+import importlib, sys
+
+def vsum(board, col):
+    sum = 0
+    for row in range(len(board)):
+        sum += board[row][col]
+    return sum
+
+def explore(board, solution, r, n, horz, vert):
+    global solutions
+    if r >= len(board): # we may have a solution
+        solved = True
+        for i in range(len(solution)):
+            if vsum(solution, i) != vert[i]:
+                solved = False
+                break
+        if solved:
+            solutions = solutions + 1
+            print("{0:3d}: {1}".format(solutions, solution))
+    else:
+        for i in range(1 << n): # exercise all elements
+            k = i
+            row = []
+            for j in range(n):
+                row.append(0 if k % 2 == 0 else board[r][j])
+                k >>= 1
+            # did we solve this row?
+            if (sum(row)) == horz[r]:
+                solution[r] = row
+                # try the next row
+                explore(board, solution, r + 1, n, horz, vert)
+
+def solve(board):
+    global solutions
+    # extract sums from board
+    vert = board.pop()  # vertical sums
+    horz = []   # horizontal sums
+    for r in range(len(board)):
+        horz.append(board[r].pop())
+    print("board = {}\n horz = {}\n vert = {}".format(board, horz, vert))
+    solutions = 0
+    explore(board, board[:], 0, len(board[0]), horz, vert)
+
+if __name__ == "__main__":
+    # solve(board)
+    if len(sys.argv) < 2:
+        print("Usage: " + sys.argv[0] + " <board file> [...]")
+    else:
+        for b in range(1, len(sys.argv)):
+            m = importlib.import_module(sys.argv[b])
+            solve(m.board)