Objective: – Given a binary tree and X, write an algorithm to Print all the paths starting from root so that sum of all the nodes in path equals to a given number. Example:

Approach:

Create a global variable as String = path.

Do the preorder

if root is greater than Sum required, return.

If not then, add root to the path and update the required sum (sum=sum-root.data).

if sum required =0, means we have found the path, print it.

See the code for better understanding.

Code:

Output:

1 2 7
1 3 6

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If you find anything incorrect or you feel that there is any better approach to solve the above problem, please write comment.
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By doing the preorder traversal, on the left branch all of the 1, 2, 7 and 5 nodes will be added; is that a valid scenario? Since I’m asking I guess that is not a valid path.

The solution also does not catch the scenario where sum = 12. In that context, the path would consist only of nodes 2, 1, 3 and 6. I’d guess that is a valid path in the tree, right?

tutorialhorizon

Thanks Eugen. It was a solution for some other problem. I have updated the post. Do let me know if you find issues in other posts.