添加了python版本代码

为数据结构和算法文件夹下的代码增加了python语言版本

animation-simulation/数据结构和算法/翻转对.md

@@ -40,6 +40,8 @@
 
 是不是很容易理解啊，那我们直接看代码吧，仅仅是在归并排序的基础上加了几行代码。
 
+Java Code:
+
 ```java
 class Solution {
     private int count;
@@ -95,3 +97,56 @@ class Solution {
 }
 ```
 
+Python Code:
+
+```python
+from typing import List
+class Solution:
+    count = 0
+    def reversePairs(self, nums: List[int])->int:
+        self.count = 0
+        self.merge(nums, 0, len(nums) - 1)
+        return self.count
+
+    def merge(self, nums: List[int], left: int, right: int):
+        if left < right:
+            mid = left + ((right - left) >> 1)
+            self.merge(nums, left, mid)
+            self.merge(nums, mid + 1, right)
+            self.mergeSort(nums, left, mid, right)
+
+    def mergeSort(self, nums: List[int], left: int, mid: int, right: int):
+
+        temparr = [0] * (right - left + 1)
+        temp1 = left
+        temp2 = mid + 1
+        index = 0
+        while temp1 <= mid and temp2 <= right:
+            # 这里需要防止溢出
+            if nums[temp1] > 2 * nums[temp2]:
+                self.count += mid - temp1 + 1
+                temp2 += 1
+            else:
+                temp1 += 1
+            
+        # 记得归位，我们还要继续使用
+        temp1 = left
+        temp2 = mid + 1
+        # 归并排序
+        while temp1 <= mid and temp2 <= right:
+            if nums[temp1] <= nums[temp2]:
+                temparr[index] = nums[temp1]
+                index += 1
+                temp1 += 1
+            else:
+                temparr[index] = nums[temp2]
+                index += 1
+                temp2 += 1
+        # 照旧
+        if temp1 <= mid:
+             temparr[index: index + mid - temp1 + 1] = nums[temp1: temp1 + mid - temp1 + 1]
+        if temp2 <= right:  
+            temparr[index: index + right - temp2 + 1] = nums[temp2: temp2 + right - temp2 + 1]
+        nums[left: left + right- left + 1] = temparr[0: right - left + 1]
+```
+