C语言 | Leetcode C语言题解之第324题摆动排序II

题目：

题解：

static inline void swap(int *a, int *b) {int c = *a;*a = *b;*b = c;
}static inline int partitionAroundPivot(int left, int right, int pivot, int *nums) {int pivotValue = nums[pivot];int newPivot = left;swap(&nums[pivot], &nums[right]);for (int i = left; i < right; ++i) {if (nums[i] > pivotValue) {swap(&nums[i], &nums[newPivot++]);}}swap(&nums[right], &nums[newPivot]);return newPivot;
}static int findKthLargest(int* nums, int numsSize, int k) {int left = 0, right = numsSize - 1;srand(time(0));while (left <= right) {int pivot = rand() % (right - left + 1) + left;int newPivot = partitionAroundPivot(left, right, pivot, nums);if (newPivot == k - 1) {return nums[newPivot];} else if (newPivot > k - 1) {right = newPivot - 1;} else { left = newPivot + 1;}}return nums[k - 1];
}static inline int transAddress(int i, int n) {return (2 * n - 2 * i - 1) % (n | 1);
}void wiggleSort(int* nums, int numsSize) {int x = (numsSize + 1) / 2;int mid = x - 1;int target = findKthLargest(nums, numsSize, numsSize - mid);for (int k = 0, i = 0, j = numsSize - 1; k <= j; k++) {if (nums[transAddress(k, numsSize)] > target) {while (j > k && nums[transAddress(j, numsSize)] > target) {j--;}swap(&nums[transAddress(k, numsSize)], &nums[transAddress(j--, numsSize)]);}if (nums[transAddress(k, numsSize)] < target) {swap(&nums[transAddress(k, numsSize)], &nums[transAddress(i++, numsSize)]);}}
}