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Author: jasoncao11

57. 数组中的第K个最大元素.md

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+***给定整数数组 nums 和整数 k，请返回数组中第 k 个最大的元素。***
+
+![algo27](./images/algo27.jpg)
+
+```
+class Solution:
+    def findKthLargest(self, nums: List[int], k: int) -> int:
+
+        def partition(nums, left, right):
+            pivot = nums[right]
+            i = left
+            for j in range(left, right+1):
+                if nums[j] < pivot:
+                    nums[i], nums[j] = nums[j], nums[i]
+                    i += 1
+            nums[i], nums[j] = nums[j], nums[i]
+            return i
+
+        n = len(nums)
+        left = 0
+        right = n-1
+        target = n-k
+        while True:
+            index = partition(nums, left, right)
+            if index == target:
+                return nums[index]
+            elif index < target:
+                left = index+1
+            else:
+                right = index-1
+
+```