Add maxheap version using _heapify_max, _heappop_max, and _heap_replace_max.

Author: Chris Cooper

python/1046-last-stone-weight.py

@@ -11,3 +11,19 @@ def lastStoneWeight(self, stones: List[int]) -> int:
 
         stones.append(0)
         return abs(stones[0])
+
+# There's a private _heapify_max method.
+# https://github.com/python/cpython/blob/1170d5a292b46f754cd29c245a040f1602f70301/Lib/heapq.py#L198
+class Solution(object):
+    def lastStoneWeight(self, stones):
+        heapq._heapify_max(stones)
+        while len(stones) > 1:
+            max_stone = heapq._heappop_max(stones)
+            diff = max_stone - stones[0]
+            if diff:
+                heapq._heapreplace_max(stones, diff)
+            else:
+                heapq._heappop_max(stones)
+        
+        stones.append(0)
+        return stones[0]