JAVASCRIPT

rotate array by d elements javascript

// Program for arr rotation by d elements.

// Approch-1 (using temp arr)
function arrayRotate1(arr, d){
    let temp =[];
    let j=0;
    for(let i=0; i<d; i++){
        temp.push(arr[i]);
    }
    for(let i=0;i<arr.length-d;i++){
        arr[i]=arr[i+d];
    }
    for(let i=arr.length-d;i<arr.length;i++){
        arr[i]=temp[j++];
    }
    return arr;
}
/**
 * Time Complexity -> O(n)
 * Space Complexity -> O(d)
 */

// Approch-2 (Rotate by one by one)
function leftRotateByOne(arr){
    let temp = arr[0];
    for(let i=0;i<arr.length;i++){
        arr[i] = arr[i+1];
    }
    arr[arr.length-1] = temp;
}

function arrayRotate2(arr, d){
    for(let i=0;i<d;i++){
        leftRotateByOne(arr);
    }
    return arr;
}
/**
 * Time Complexity ->O(n*d)
 * Space Complexity -> O(1)
 */


const arr = [1,2,3,4,5,6,7];
const d=2;
console.log(arrayRotate2(arr,d));
/**
 * output->
 * [ 3, 4, 5, 6,7, 1, 2]
 */