[容易]中位数

题目来源：http://www.lintcode.com/zh-cn/problem/median/

C++版 VS2012测试通过

方法一

 1 class Solution {
 2 public:
 3     /**
 4      * @param nums: A list of integers.
 5      * @return: An integer denotes the middle number of the array.
 6      */
 7     int median(vector<int> &nums) {
 8         // write your code here
 9         sort(nums.begin(),nums.end());
10         if(nums.size()%2==0)
11             return nums.at(nums.size()/2-1);
12         else
13             return nums.at((nums.size()-1)/2);
14     }
15 };

方法二

 1 class Solution {
 2 public:
 3     /**
 4      * @param nums: A list of integers.
 5      * @return: An integer denotes the middle number of the array.
 6      */
 7     int median(vector<int> &nums) {
 8         // write your code here
 9         int k = (nums.size() + 1) / 2;
10         priority_queue<int> que;
11         int len = nums.size();
12         for(int i = 0; i < len; i ++) {
13             if(que.size() == k) {
14                 if(nums[i] < que.top()) {
15                     que.pop();
16                     que.push(nums[i]);
17                 }
18             }else {
19                 que.push(nums[i]);
20             }
21         }
22         return que.top();
23     }
24 };

Python2.7版 spider测试通过

 1 class Solution:
 2     """
 3     @param nums: A list of integers.
 4     @return: An integer denotes the middle number of the array.
 5     """
 6     def median(self, nums):
 7         # write your code here
 8         nums.sort()
 9         return nums[(len(nums)-1)/2]
10
11 #测试
12 #if __name__==‘__main__‘:
13 #    n=[4,5,7,9]
14 #    s=Solution()
15 #    print s.median(n)