添加0347前K个高频元素 python3 版本

problems/0347.前K个高频元素.md

@@ -162,6 +162,63 @@ class Solution {
 
 
 Python：
+```python
+class Solution:
+    def sift(self, alist, low, high):
+        '''小根堆构建'''
+        i = low 
+        j = 2 * i + 1
+        tmp = alist[low]
+        while j <= high:
+            if j + 1 <= high and alist[j+1] <= alist[j]:
+                j += 1
+            if alist[j] < tmp:
+                alist[i] = alist[j]
+                i = j 
+                j = 2 * i + 1
+            else:
+                alist[i] = tmp
+                break
+        else:
+            alist[i] = tmp
+
+
+    def topK(self, nums, k):
+        # 建立小根堆
+        heap = nums[:k]
+        for i in range((k-2)//2, -1, -1):
+            self.sift(heap, i, k-1)
+        
+        # 把后续的k到len(nums)填充到小根堆里
+        for i in range(k, len(nums)):
+            if nums[i] >= heap[0]:
+                heap[0] = nums[i]
+                self.sift(heap, 0, k-1)
+
+        # 排序
+        for i in range(k-1, -1, -1):
+            heap[0], heap[i]= heap[i], heap[0]
+            self.sift(heap, 0, i-1)
+        return heap
+        
+    def topKFrequent(self, nums: List[int], k: int) -> List[int]:
+        dict1 = dict()
+        for val in nums:
+            if val not in dict1:
+                dict1[val] = 1
+            else:
+                dict1[val] += 1
+        res = list()
+        ind = list()
+        for item in dict1:
+            res.append([dict1[item], item])
+        result = list()
+        heap = self.topK(res, k)
+        print(heap)
+        for val in heap:
+            result.append(val[1])
+        return result
+```
 
 
 Go：