How to add cache for solution to LeetCode Sum of Distances in Tree?

I am working on 834. Sum of Distances in Tree:

How to add cache for solution to LeetCode Sum of Distances in Tree?

I am working on 834. Sum of Distances in Tree:

How to add cache for solution to LeetCode Sum of Distances in Tree?

I am working on 834. Sum of Distances in Tree:

How to add cache for solution to LeetCode Sum of Distances in Tree?

I am working on 834. Sum of Distances in Tree:

How to add cache for solution to LeetCode Sum of Distances in Tree?

I am working on 834. Sum of Distances in Tree:

How to add cache for solution to LeetCode Sum of Distances in Tree?

I am working on 834. Sum of Distances in Tree:

How to add cache for solution to LeetCode Sum of Distances in Tree?

I am working on 834. Sum of Distances in Tree: