【leetcode】462. Minimum Moves to Equal Array Elements II【M】

Given a non-empty integer array, find the minimum number of moves required to make all array elements equal, where a move is incrementing a selected element by 1 or decrementing a selected element by 1.

You may assume the array's length is at most 10,000.

Example:

Input:
[1,2,3]

Output:
2

Explanation:
Only two moves are needed (remember each move increments or decrements one element):

[1,2,3]  =>  [2,2,3]  =>  [2,2,2]

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剛開始想的是，那就讓所有數都變成中位數，正如所有人都嘗試過的那樣，錯了

甚至想到了最小二乘法和線性迴歸方程，不過太麻煩了

那應該怎麼弄呢，看了discuss，發現應該是中位數，那是爲什麼呢？

沒聽說中位數也沒這樣的性質啊、

然後看到了這樣一個code，就明白了

        while(i < j){

            count += nums[j]-nums[i];

            i++;

            j--;

        }

就是排序之後，從兩邊往中間走，最大和最小之間的差距，是一定要填補上的，不管+1 還是 -1

這樣，走到中間，那就是中位數了

妙

class Solution(object):
    def minMoves2(self, nums):
        
        nums.sort()
        
        t = nums[len(nums)/2]
        
        res= 0
        for i in nums:
            res += abs(i - t)
            
        return res