Leetcode problem 50 - Create Target Array in the Given Order

Given two arrays of integers nums and index. Your task is to create target array under the following rules:

Initially target array is empty. From left to right read nums[i] and index[i], insert at index index[i] the value nums[i] in target array. Repeat the previous step until there are no elements to read in nums and index. Return the target array.

It is guaranteed that the insertion operations will be valid.

Example 1:

Input: nums = [0,1,2,3,4], index = [0,1,2,2,1] Output: [0,4,1,3,2] Explanation: nums index target 0 0 [0] 1 1 [0,1] 2 2 [0,1,2] 3 2 [0,1,3,2] 4 1 [0,4,1,3,2] Example 2:

Input: nums = [1,2,3,4,0], index = [0,1,2,3,0] Output: [0,1,2,3,4] Explanation: nums index target 1 0 [1] 2 1 [1,2] 3 2 [1,2,3] 4 3 [1,2,3,4] 0 0 [0,1,2,3,4] Example 3:

Input: nums = [1], index = [0] Output: [1]

Constraints:

1 <= nums.length, index.length <= 100 nums.length == index.length 0 <= nums[i] <= 100 0 <= index[i] <= i

/**
 * @param {number[]} nums
 * @param {number[]} index
 * @return {number[]}
 */
var createTargetArray = function (nums, index) {
  let arr = [];
  for (let i = 0; i < nums.length; i++) {
    arr.splice(index[i], 0, nums[i]);
  }
  return arr;
};

The JavaScript function createTargetArray takes two arrays, nums and index, as input. It aims to create a new array arr by inserting elements from nums at specified positions determined by the corresponding values in the index array. It does so by iterating through nums, and for each element, it uses the splice method to insert it at the specified index in the arr array. After processing all elements, it returns the resulting arr. Essentially, this function constructs a target array based on the values in nums and their insertion positions defined in the index array.