Add Python

LokiSharp · web-flow · commit bb97a1e20055 · 2017-01-21T23:58:59.000+08:00
diff --git a/7.heapSort.md b/7.heapSort.md
@@ -71,4 +71,38 @@ function heapSort(arr) {
     }
     return arr;
 }
-```
+```
+## 4. Python 代码实现
+
+```python
+def buildMaxHeap(arr):
+    import math
+    for i in range(math.floor(len(arr)/2),-1,-1):
+        heapify(arr,i)
+
+def heapify(arr, i):
+    left = 2*i+1
+    right = 2*i+2
+    largest = i
+    if left < arrLen and arr[left] > arr[largest]:
+        largest = left
+    if right < arrLen and arr[right] > arr[largest]:
+        largest = right
+
+    if largest != i:
+        swap(arr, i, largest)
+        heapify(arr, largest)
+
+def swap(arr, i, j):
+    arr[i], arr[j] = arr[j], arr[i]
+
+def heapSort(arr):
+    global arrLen
+    arrLen = len(arr)
+    buildMaxHeap(arr)
+    for i in range(len(arr)-1,0,-1):
+        swap(arr,0,i)
+        arrLen -=1
+        heapify(arr, 0)
+    return arr
+```
