# LeetCode - 1968. Array With Elements Not Equal to Average of Neighbors
### 題目網址：https://leetcode.com/problems/array-with-elements-not-equal-to-average-of-neighbors/
###### tags: `LeetCode` `Medium`

/*
    -LeetCode format-
    Problem: 1968. Array With Elements Not Equal to Average of Neighbors
    Difficulty: Medium
    
    by Inversionpeter
*/



#define REINDEX(i) (nums[((i << 1) + 1) % (nums.size() | 1)])

static const auto Initialize = [] {
	ios::sync_with_stdio(false); cin.tie(nullptr);
	return nullptr;
}();

class Solution {
public:
    vector<int> rearrangeArray(vector<int>& nums) {
        vector <int>::iterator middle = nums.begin() + (nums.size() >> 1);
        nth_element(nums.begin(), middle, nums.end());
        int median = *middle, i = 0, j = 0, k = nums.size() - 1;
        while (j <= k)
            if (REINDEX(j) > median) {
                swap(REINDEX(i), REINDEX(j));
                ++i; ++j;
            }
            else if (REINDEX(j) < median) {
                swap(REINDEX(j), REINDEX(k));
                --k;
            }
            else
                ++j;
        return nums;
    }
};