// 1968. Array With Elements Not Equal to Average of Neighbors #include "leetcode.h" /* * you are given a 0-indexed array 'nums' of distinct integers. you want to * rearrange the elements in the array such that every element in the rearranged * array is not equal to the average of its neighbors. more formally the * rearranged array should have the property such that for every 'i' in the * range '1 <= nums.len - 1', '(nums[i - 1] + nums[i + 1]) / 2' is not equal to * 'nums[i]'. return any rearrangement of 'nums' that meets the requirements. */ void swap(int *x, int *y) { if (x == y) return; *x ^= *y; *y ^= *x; *x ^= *y; } int *rearrangeArray(int *nums, int numsSize, int *returnSize) { int *ans = (int *)malloc(numsSize * sizeof(int)), i, j = 0; *returnSize = numsSize; for (int i = 1; i < numsSize - 1; i++) if (nums[i] * 2 == nums[i - 1] + nums[i + 1]) swap(&nums[i], &nums[i + 1]); for (int i = numsSize - 2; i; i--) if (nums[i] * 2 == nums[i - 1] + nums[i + 1]) swap(&nums[i], &nums[i - 1]); return ans; } int main() { int n1[] = {1, 2, 3, 4, 5}, n2[] = {6, 2, 0, 9, 7}, rs1, rs2; int *ra1 = rearrangeArray(n1, ARRAY_SIZE(n1), &rs1); int *ra2 = rearrangeArray(n2, ARRAY_SIZE(n2), &rs2); for (int i = 0; i < rs1; i++) printf("%d ", ra1[i]); // expect: 1,2,4,5,3 printf("\n"); for (int i = 0; i < rs2; i++) printf("%d ", ra2[i]); // expect: 9,7,6,2,0 printf("\n"); free(ra1), free(ra2); }