题目：

题解：

func wiggleSort(nums []int) {     n := len(nums)     x := (n + 1) / 2     target := quickSelect(nums, x-1)      transAddress := func(i int) int { return (2*n - 2*i - 1) % (n | 1) }     for k, i, j := 0, 0, n-1; k <= j; k++ {         tk := transAddress(k)         if nums[tk] > target {             for j > k && nums[transAddress(j)] > target {                 j--             }             tj := transAddress(j)             nums[tk], nums[tj] = nums[tj], nums[tk]             j--         }         if nums[tk] < target {             ti := transAddress(i)             nums[tk], nums[ti] = nums[ti], nums[tk]             i++         }     } }  func quickSelect(a []int, k int) int {     rand.Seed(time.Now().UnixNano())     rand.Shuffle(len(a), func(i, j int) { a[i], a[j] = a[j], a[i] })     for l, r := 0, len(a)-1; l < r; {         pivot := a[l]         i, j := l, r+1         for {             for i++; i < r && a[i] < pivot; i++ {             }             for j--; j > l && a[j] > pivot; j-- {             }             if i >= j {                 break             }             a[i], a[j] = a[j], a[i]         }         a[l], a[j] = a[j], pivot         if j == k {             break         } else if j < k {             l = j + 1         } else {             r = j - 1         }     }     return a[k] }