Rotate array - Given an array, rotate the array to the right by k steps, where k is non-negative.

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Array Problem question :

189.Given an array, rotate the array to the right by k steps, where k is non-negative.

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]

Efficient Algorithm

Step1 : reverse the whole array from first element to last element;
Step2: reverse the array from first element to the k-1 element;
Step3: reverse the array from kth element to the last element;

General reverse method :
while starting element is less than ending element:
replace start and end
start++
end--;