LeetCode 462. Minimum Moves to Equal Array Elements II

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]

题目大意:给一个非空整数数组,每次可以将数组中一个元素+1或者-1,求最少需要多少次这样的操作,才能使数组中所有的数都想等~

分析:让所有数都等于那个第n/2 + 1大的数字~首先用nth_element(nums.begin(), nums.begin() + n / 2, nums.end());将第n/2 + 1大的数字放到最中间,然后取得它的值为mid,最后遍历数组,累加所有元素与mid的差的绝对值即为所求~