Return value in the proble,

#1

Please explain the return statement in this problem?

#2

Hello @sahazeer123,

For finding the maximum sum path, you are performing four computations in each function call:

  1. return_val_left_subtree + root->data + return_val_right_subtree
  2. return_val_left_subtree + root->data
  3. root->data + return_val_right_subtree
  4. root->data

But, while returning a value, you have to compare only 2, 3 and 4th.
Reason:
Let us consider an example:
_____________ 1
_______2
____3 ______20

When you are at 2, maximum sum path will have value 25 for point 1.
But, when you will return a value for the parent, you have to consider one of the two possible paths i.e.
either 2->3 or 2->20
reason:
Because 1 cannot have both 3 and 20 in the same path.
So, you choose to return the path with maximum sum.

Also for the cases like:
_____________ 1
_______2
____-3 ______-20

You will return root->data

Finally, you return max(2.,3.,4.)

Hope, this would help.
Give a like if you are satisfied.

1 Like
#3

Thank you.Very intuitive explanaion

#4

Anytime @sahazeer123,

Please, mark it as resolved.