Given an integer array nums
, reorder it such that nums[0] < nums[1] > nums[2] < nums[3]...
.
You may assume the input array always has a valid answer.
Example 1:
Input: nums = [1,5,1,1,6,4] Output: [1,6,1,5,1,4] Explanation: [1,4,1,5,1,6] is also accepted.
Example 2:
Input: nums = [1,3,2,2,3,1] Output: [2,3,1,3,1,2]
Constraints:
1 <= nums.length <= 5 * 104
0 <= nums[i] <= 5000
nums
.Follow Up: Can you do it in
O(n)
time and/or in-place with O(1)
extra space?struct Solution;
impl Solution {
fn wiggle_sort(nums: &mut Vec<i32>) {
let n = nums.len();
let mut sorted = nums.to_vec();
sorted.sort_unstable();
let k = if n % 2 == 0 { n / 2 } else { n / 2 + 1 };
for i in 0..k {
nums[i * 2] = sorted[k - 1 - i];
}
for i in 0..(n - k) {
nums[i * 2 + 1] = sorted[n - 1 - i];
}
}
}
#[test]
fn test() {
let mut nums = vec![1, 5, 1, 1, 6, 4];
let res = vec![1, 6, 1, 5, 1, 4];
Solution::wiggle_sort(&mut nums);
assert_eq!(nums, res);
let mut nums = vec![1, 1, 2, 1, 2, 2, 1];
let res = vec![1, 2, 1, 2, 1, 2, 1];
Solution::wiggle_sort(&mut nums);
assert_eq!(nums, res);
let mut nums = vec![4, 5, 5, 6];
let res = vec![5, 6, 4, 5];
Solution::wiggle_sort(&mut nums);
assert_eq!(nums, res);
}