Codevita 2017 Round-1 Problem-C

    /*
     Author: Krishankant Ray
     * CodeVita 2017 Round 1
     */

    #include<iostream>
    #include<vector>

    using namespace std;
    int main()
    {
        int d,k=0;
        string arr;
        cin>>d;
        cin>>arr;
        int n=arr.length();
        char R[n];

        for(int f=0; f<n; )
        {

            R[f]=arr[k++];

            f+=((2*d)-2);
        }
        for(int i=1; i<d-1;i++)
        {
            R[i]=arr[k++];
            for(int j=i; j<n;)
            {

                j+=((2*d)-2-(2*i));
                R[j]=arr[k++];

                j+=((2*i));
                if(j<n)
                R[j]=arr[k++];

            }
        }

        for(int l=d-1; l<n;l+=((2*d)-2))
        {
            R[l]=arr[k++];

        }
        for(int f=0; f<n;f++)
        {
            if(R[f]=='X')
                break;
            else
            cout<<R[f];
        }

        return 0;
    }