189_Rotate_Array

Leetocde 189: Rotate Array
Detailed video Explanation: https://youtu.be/5D9OrHsw3M0
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C++:
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class Solution {
public:
    void rotate(vector<int>& nums, int k) {
        int n = nums.size();
        k %= n;
        reverse(nums.begin(), nums.begin()+n-k);
        reverse(nums.begin() + n - k, nums.end());
        reverse(nums.begin(), nums.end());
    }
};



Java:
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class Solution {
    public void reverse(int[] nums, int l, int r){
        while(l < r){
            int temp = nums[l];
            nums[l] = nums[r];
            nums[r] = temp;
            l++;
            r--;
        }
    }
    public void rotate(int[] nums, int k) {
        int n = nums.length;
        k %= n;
        reverse(nums, 0, n-k-1);
        reverse(nums, n - k, n - 1);
        reverse(nums, 0, n-1);
    }
}



Python3:
--------
class Solution:
    def reverse(self, nums, l, r):
        while l < r:
            nums[l], nums[r] = nums[r], nums[l]
            l += 1
            r -= 1
            
    def rotate(self, nums: List[int], k: int) -> None:
        """
        Do not return anything, modify nums in-place instead.
        """
        n = len(nums)
        k %= n
        self.reverse(nums, 0, n-k-1)
        self.reverse(nums, n - k, n - 1)
        self.reverse(nums, 0, n-1)