[Swift]LeetCode703. 数据流中的第K大元素 | Kth Largest Element in a Stream

Design a class to find the kth largest element in a stream. Note that it is the kth largest element in the sorted order, not the kth distinct element.

Your KthLargest class will have a constructor which accepts an integer kand an integer array nums, which contains initial elements from the stream. For each call to the method KthLargest.add, return the element representing the kth largest element in the stream.

Example:

int k = 3;
int[] arr = [4,5,8,2];
KthLargest kthLargest = new KthLargest(3, arr);
kthLargest.add(3);   // returns 4
kthLargest.add(5);   // returns 5
kthLargest.add(10);  // returns 5
kthLargest.add(9);   // returns 8
kthLargest.add(4);   // returns 8

Note: 
You may assume that nums' length ≥ k-1 and k ≥ 1.

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设计一个找到数据流中第K大元素的类（class）。注意是排序后的第K大元素，不是第K个不同的元素。

你的 KthLargest 类需要一个同时接收整数 k 和整数数组nums 的构造器，它包含数据流中的初始元素。每次调用 KthLargest.add，返回当前数据流中第K大的元素。

示例:

int k = 3;
int[] arr = [4,5,8,2];
KthLargest kthLargest = new KthLargest(3, arr);
kthLargest.add(3);   // returns 4
kthLargest.add(5);   // returns 5
kthLargest.add(10);  // returns 5
kthLargest.add(9);   // returns 8
kthLargest.add(4);   // returns 8

说明: 
你可以假设 nums 的长度≥ k-1 且k ≥ 1。

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Time Limit Exceeded

 1 class KthLargest {
 2     var st:[Int] = [Int]()
 3     var K:Int = 0
 4 
 5     init(_ k: Int, _ nums: [Int]) {
 6         var nums = nums
 7         nums.sort()
 8         for num in nums
 9         {
10             st.append(num)
11             if st.count > k
12             {
13                 st.removeFirst()
14             }
15         }        
16         K = k        
17     }
18     
19     func add(_ val: Int) -> Int {
20         st.append(val)
21         st.sort()
22         if st.count > K
23         {
24             st.removeFirst()
25         }
26         return st.first!   
27     }
28 }
29 
30 /**
31  * Your KthLargest object will be instantiated and called as such:
32  * let obj = KthLargest(k, nums)
33  * let ret_1: Int = obj.add(val)
34  */
35