Rotate Array
Given an array, rotate the array to the right by k steps, where k is non-negative.
Follow up:
Try to come up as many solutions as you can, there are at least 3 different ways to solve this problem.
Could you do it in-place with O(1) extra space?
Example 1:
Input: nums = [1,2,3,4,5,6,7], k = 3
Output: [5,6,7,1,2,3,4]
Explanation:
rotate 1 steps to the right: [7,1,2,3,4,5,6]
rotate 2 steps to the right: [6,7,1,2,3,4,5]
rotate 3 steps to the right: [5,6,7,1,2,3,4]
Example 2:
Input: nums = [-1,-100,3,99], k = 2
Output: [3,99,-1,-100]
Explanation:
rotate 1 steps to the right: [99,-1,-100,3]
rotate 2 steps to the right: [3,99,-1,-100]
Constraints:
1 <= nums.length <= 2 * 10^4
It's guaranteed that
nums[i]
fits in a 32 bit-signed integer.k >= 0
class Solution {
public void swap(int[] nums, int i, int j) {
int temp = nums[i];
nums[i] = nums[j];
nums[j] = temp;
}
public void rotate(int[] nums, int k) {
k = k % nums.length;
int i = 0, j = nums.length - k - 1;
while (i < j)
swap(nums, i++, j--);
i = nums.length - k;
j = nums.length - 1;
while (i < j)
swap(nums, i++, j--);
i = 0;
j = nums.length - 1;
while (i < j)
swap(nums, i++, j--);
}
}
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