Given an array, rotate the array to the right by k steps, where k is non-negative.
Follow up:
Try to come up with 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
public class Solution {
public void Rotate(int[] nums, int k) {
if(k>nums.Length){
k = k % nums.Length;
}
Reverse(nums,0,nums.Length-1);
Reverse(nums,0,k-1);
Reverse(nums,k,nums.Length-1);
}
private void Reverse(int[] nums, int start, int end){
while(start < end){
int temp = nums[start];
nums[start] = nums[end];
nums[end] = temp;
start++;
end--;
}
}
}Time Complexity: O(n)
Space Complexity: O(1)
