function absolutePermutation($n, $k) {
    $index = [];
    
    for($i = 1; $i <= $n; $i++) {
        $index[$i] = true;
    }

    $found = 0;
    $p = [];
    for($number = 1; $number <= $n; $number++) {
        $need1 = $k + $number;
        $need2 = abs($k - $number);
        if(abs($need2 - $number) === $k && ($index[$need2] ?? false)) {
            $index[$need2] = false;
            $p[] = $need2;
            $found++;
        } else if (abs($need1 - $number) === $k && ($index[$need1] ?? false)) {
            $index[$need1] = false;
            $p[] = $need1;
            $found++;
        }
    }
    
    return $found === $n ? $p : [-1];
}

function absolutePermutation(n, k) {
   const useSet = new Set();
   const res = [];
   
   for(let i = 1; i<=n; i++){
    if((i-k)>=1 && !useSet.has(i-k)){
        res.push(i-k);
        useSet.add(i-k);
    } else if((i+k) <= n && !useSet.has(i+k)){
        res.push(i+k);
        useSet.add(i+k);
    } else{
        return [-1];
    }
   }
   
   return res;
}

public static List<Integer> absolutePermutation(int n, int k) {
    List<Integer> result = new ArrayList<>();
    boolean[] used = new boolean[n + 1];

    for (int i = 1; i <= n; i++) {
        if (i - k > 0 && !used[i - k]) {
            result.add(i - k);
            used[i - k] = true;
        } else if (i + k <= n && !used[i + k]) {
            result.add(i + k);
            used[i + k] = true;
        } else {
            return Arrays.asList(-1);
        }
    }
    return result;
}