C++ で最初の N 個の数値を K 個の距離だけ離れるように並べ替えます。

#include <bits/stdc++.h>
using namespace std;
void Rearrangement(int n, int k){
   int temp = n % (2 * k);
   int ptr[n + 1];
   if(k == 0){
      for(int i = 1; i <= n; i++){
         cout << i << " ";
      }
      return;
   }
   if(temp != 0){
      cout<<"Not Possible";
      return;
   }
   for(int i = 1; i <= n; i++){
      ptr[i] = i;
   }
   for(int i = 1; i <= n; i += 2 * k){
      for(int j = 1; j <= k; j++){
         swap(ptr[i + j - 1], ptr[k + i + j - 1]);
      }
   }
   for(int i = 1; i <= n; i++){
      cout << ptr[i] << " ";
   }
}
int main(){
   int n = 20;
   int k = 2;
   cout<<"Rearrangement of first N numbers to make them at K distance is: ";
   Rearrangement(n, k);
   return 0;
}

Rearrangement of first N numbers to make them at K distance is: 3 4 1 2 7 8 5 6 11 12 9 10 15 16 13 14 19 20 17 18