1389. 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.

O(N^2) Time Solution

• Brute force

Code

class Solution{
public:
    vector<int> createTargetArray(vector<int> &nums, vector<int> &index)
    {
        vector<int> ans;
        int n = nums.size();
        for (int i = 0; i < n; i++)
            ans.insert(ans.begin() + index[i], nums[i]);
        return ans;
    }
};

O(NlogN) based on “smaller elements after self”.

• It is HARD level problem
• Will be added soon…