<p>You are given an integer array <code>receiver</code> of length <code>n</code> and an integer <code>k</code>. <code>n</code> players are playing a ball-passing game.</p>

<p>You choose the starting player, <code>i</code>. The game proceeds as follows: player <code>i</code> passes the ball to player <code>receiver[i]</code>, who then passes it to <code>receiver[receiver[i]]</code>, and so on, for <code>k</code> passes in total. The game&#39;s score is the sum of the indices of the players who touched the ball, including repetitions, i.e. <code>i + receiver[i] + receiver[receiver[i]] + ... + receiver<sup>(k)</sup>[i]</code>.</p>

<p>Return&nbsp;the <strong>maximum</strong>&nbsp;possible score.</p>

<p><strong>Notes:</strong></p>

<ul>
	<li><code>receiver</code> may contain duplicates.</li>
	<li><code>receiver[i]</code> may be equal to <code>i</code>.</li>
</ul>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">receiver = [2,0,1], k = 4</span></p>

<p><strong>Output:</strong> <span class="example-io">6</span></p>

<p><strong>Explanation:</strong></p>

<p>Starting with player <code>i = 2</code> the initial score is 2:</p>

<table>
	<tbody>
		<tr>
			<th>Pass</th>
			<th>Sender Index</th>
			<th>Receiver Index</th>
			<th>Score</th>
		</tr>
		<tr>
			<td>1</td>
			<td>2</td>
			<td>1</td>
			<td>3</td>
		</tr>
		<tr>
			<td>2</td>
			<td>1</td>
			<td>0</td>
			<td>3</td>
		</tr>
		<tr>
			<td>3</td>
			<td>0</td>
			<td>2</td>
			<td>5</td>
		</tr>
		<tr>
			<td>4</td>
			<td>2</td>
			<td>1</td>
			<td>6</td>
		</tr>
	</tbody>
</table>
</div>

<p><strong class="example">Example 2:</strong></p>

<div class="example-block">
<p><strong>Input:</strong> <span class="example-io">receiver = [1,1,1,2,3], k = 3</span></p>

<p><strong>Output:</strong> <span class="example-io">10</span></p>

<p><strong>Explanation:</strong></p>

<p>Starting with player <code>i = 4</code> the initial score is 4:</p>

<table>
	<tbody>
		<tr>
			<th>Pass</th>
			<th>Sender Index</th>
			<th>Receiver Index</th>
			<th>Score</th>
		</tr>
		<tr>
			<td>1</td>
			<td>4</td>
			<td>3</td>
			<td>7</td>
		</tr>
		<tr>
			<td>2</td>
			<td>3</td>
			<td>2</td>
			<td>9</td>
		</tr>
		<tr>
			<td>3</td>
			<td>2</td>
			<td>1</td>
			<td>10</td>
		</tr>
	</tbody>
</table>
</div>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= receiver.length == n &lt;= 10<sup>5</sup></code></li>
	<li><code>0 &lt;= receiver[i] &lt;= n - 1</code></li>
	<li><code>1 &lt;= k &lt;= 10<sup>10</sup></code></li>
</ul>

class Solution:
  def getMaxFunctionValue(self, receiver: List[int], k: int) -> int:
    n = len(receiver)
    m = int(math.log2(k)) + 1
    ans = 0
    # jump[i][j] := the the node you reach after jumping 2^j steps from i
    jump = [[0] * m for _ in range(n)]
    # summ[i][j] := the sum of the first 2^j nodes you reach when jumping from i
    summ = [[0] * m for _ in range(n)]

    for i in range(n):
      jump[i][0] = receiver[i]
      summ[i][0] = receiver[i]

    # Calculate binary lifting.
    for j in range(1, m):
      for i in range(n):
        midNode = jump[i][j - 1]
        #   the the node you reach after jumping 2^j steps from i
        # = the node you reach after jumping 2^(j - 1) steps from i
        # + the node you reach after jumping another 2^(j - 1) steps
        jump[i][j] = jump[midNode][j - 1]
        #   the sum of the first 2^j nodes you reach when jumping from i
        # = the sum of the first 2^(j - 1) nodes you reach when jumping from i
        # + the sum of another 2^(j - 1) nodes you reach
        summ[i][j] = summ[i][j - 1] + summ[midNode][j - 1]

    for i in range(n):
      currSum = i
      currPos = i
      for j in range(m):
        if (k >> j) & 1 == 1:
          currSum += summ[currPos][j]
          currPos = jump[currPos][j]
      ans = max(ans, currSum)

    return ans
5733