Topcoder SRM 687 (Div 2) 250.Quorum __ sort

Problem Statement
	In one organization they have n different committees. The organization has a very large number of employees. Each employee is a member of each committee. Each committee has a quorum: the smallest number of members that have to be present to have an official meeting. You are given a vector <int> arr with n elements. Each element of arr is the quorum of one committee. You are also given an int k. Yesterday, k different committees had an official meeting, all at the same time. Obviously, each person attended at most one of those meetings. Compute and return the smallest possible number of people who attended a meeting yesterday.
Definition
	Class: Quorum Method: count Parameters: vector <int>, int Returns: int Method signature: int count(vector <int> arr, int k) (be sure your method is public)
Limits
	Time limit (s): 2.000 Memory limit (MB): 256 Stack limit (MB): 256
Notes
-	The value of n is not given explicitly. Instead, you can determine it as the number of elements in arr.
Constraints
-	arr will contain between 1 and 50 elements, inclusive.
-	Each element of arr will be between 1 and 50.
-	k will be between 1 and the number of elements of arr, inclusive.
Examples
0)
	{5,2,3} 1 Returns: 2 There are three committees. The first committee requires 5 members to start a meeting, the second requires 2, and the third requires 3 members. As k=1, there was one meeting yesterday. The smallest possible solution is that it was a meeting of the second committee and that exactly 2 employees attended that meeting.
1)
	{1,1,1,1,1} 5 Returns: 5 All five committees had a meeting yesterday. We need at least one person per meeting. No person can attend more than one meeting. Hence, there must have been at least 5 different people.
2)
	{50,2,9,49,38} 3 Returns: 49
3)
	{20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1} 14 Returns: 105

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My Solution
the smallest number of members // this "number" is "人数" in Chinese not "序号或者编号".

sort, then get the sum of top k smallest;

// BEGIN CUT HERE

// END CUT HERE
#line 5 "Quorum.cpp"
#include <string>
#include <vector>
#include <algorithm>

using namespace std;
class Quorum {
public:
int count(vector <int> arr, int k) {
sort(arr.begin(), arr.end());
int ans = 0;
for(int i = 0; i < k; i++)
ans += arr[i];
return ans;
}
};

Thank you!

                                                                                                                                                                                                                                
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