extra/gearing-up-for-destruction/solution.py

@@ -0,0 +1,35 @@
+def solution(pegs):
+    odd, even = sum_odd_even(pegs)
+
+    if len(pegs) % 2 == 0:
+        s = 2 * odd - 2 * even - pegs[-1] + pegs[0]
+        if s <= 0:
+            return [-1, -1]
+        if s % 3 == 0:
+            return [2*s/3, 1]
+        else:
+            return [2*s, 3]
+    else:
+        s = 2 * odd - 2 * even + pegs[-1] + pegs[0]
+        if s <= 0:
+            return [-1, -1]
+        return [2*s, 1]
+
+def sum_odd_even(pegs):
+    odd, even = 0, 0
+    for i, peg in enumerate(pegs):
+        if i % 2 == 1:
+            odd += peg
+        else:
+            even += peg
+    return odd, even
+
+
+tests = [
+        ([4, 30, 50], [12, 1]),
+        ([4, 17, 50], [-1, -1]),
+        ]
+
+for i, o in tests:
+    result = solution(i)
+    print (i, result == o, result, o)