Children Sum Property

Check the problem description here.

https://www.codingninjas.com/codestudio/problems/childrensumproperty_790723?topList=striver-sde-sheet-problems&utm_source=striver&utm_medium=website&leftPanelTab=0

Solution:

As we recursively go to left and right , we replace child data , with root data, if the root is less than the root , so that while we come back the child of a node is always higher than the root. So that we can increment the root value(make it left +right data).

def changeTree(root): 
    if root ==None:
        return 
    left=0
    right=0
    if root.left!=None:
        if root.left.data<root.data:
            root.left.data=root.data
        changeTree(root.left)
        left=root.left.data
    if root.right!=None:
        if root.right.data<root.data:
            root.right.data=root.data
        changeTree(root.right)
        right=root.right.data
    if not (root.left==None and root.right==None):
        root.data=left+right

Time:O(N)

Space:O(h)