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)]);
        }
    }
}