Anjan Dutta

Leet Code 189: Rotate Array

Problem statement:

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

Constraints:

1 <= nums.length <= 105
-231 <= nums[i] <= 231 - 1
0 <= k <= 105

Soultion

/**
 * @param {number[]} nums
 * @param {number} k
 * @return {void} Do not return anything, modify nums in-place instead.
 */
var rotate = function(nums, k) {
    
    const len = nums.length;
    k = k % len;
    nums = reverse(nums, 0, len-1);
    nums = reverse(nums, 0, k-1);
    nums = reverse(nums, k, len-1);
};

function reverse(arr = [], l, r) {
    while(l<r) {
        let temp = arr[l];
        arr[l] = arr[r];
        arr[r] = temp;
        l++;
        r--;
    }
    return arr;
}