189_Rotate Array

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

Example

Input: [1,2,3,4,5,6,7] and 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]

Solution

def rotate(nums, k):
    """
    :type nums: List[int]
    :type k: int
    :rtype: void Do not return anything, modify nums in-place instead.
    """
    flag = [True] * len(nums)
    for i in range(len(nums)) :
        if flag[i]:
            value = nums[i]
            while flag[(i+k) % len(nums)]:
                j = (i+k) % len(nums)
                temp = nums[j]
                nums[j] = value
                i = j
                value = temp
                flag[j] = False