[codility] CyclicRotation

[codility] CyclicRotation

CyclicRotation.js

const assert = require('assert');

function solution(A, K) {
  const shiftedArray = [];
  let shiftedIndex;

  A.forEach((element, index) => {
    shiftedIndex = (index + K) % A.length;// 오른쪽으로 shift
    shiftedArray[shiftedIndex] = A[index];
  });

  return shiftedArray;
}

describe('Test Suite', () => {
  it('case 1', () => {
    assert.deepEqual([9, 7, 6, 3, 8], solution([3, 8, 9, 7, 6], 3));
  });
  it('case 2', () => {
    assert.deepEqual([0, 0, 0], solution([0, 0, 0], 1));
  });
  it('case 3', () => {
    assert.deepEqual([1, 2, 3, 4], solution([1, 2, 3, 4], 4));
  });
});

문제설명

An array A consisting of N integers is given. Rotation of the array means that each element is shifted right by one index, and the last element of the array is moved to the first place. For example, the rotation of array A = [3, 8, 9, 7, 6] is [6, 3, 8, 9, 7] (elements are shifted right by one index and 6 is moved to the first place).

The goal is to rotate array A K times; that is, each element of A will be shifted to the right K times.

Write a function:

class Solution { public int[] solution(int[] A, int K); }

that, given an array A consisting of N integers and an integer K, returns the array A rotated K times.

For example, given

A = [3, 8, 9, 7, 6] K = 3

the function should return [9, 7, 6, 3, 8]. Three rotations were made:

[3, 8, 9, 7, 6] -> [6, 3, 8, 9, 7] [6, 3, 8, 9, 7] -> [7, 6, 3, 8, 9] [7, 6, 3, 8, 9] -> [9, 7, 6, 3, 8]

For another example, given

A = [0, 0, 0] K = 1

the function should return [0, 0, 0]

Given

A = [1, 2, 3, 4] K = 4

the function should return [1, 2, 3, 4]

Assume that:

N and K are integers within the range [0..100];each element of array A is an integer within the range [−1,000..1,000].

In your solution, focus on correctness. The performance of your solution will not be the focus of the assessment.

테스트 코드도 짜봤는데 assert.equal이 배열안의 원소를 비교하는게 아니라 주소값을 비교해서 그냥 코드를 없앴다.

종호형이 deepEqual이라는 메소드를 알려주셨다. 객체 내부까지 비교해주는 function인 것 같다.