Lowest common anscestor in binary tree

#1

please provide the code as explained in the video,
and also for the case if a is present and b is not ,

here prateek sir assume that both a and b are present , but what if b is not present , please share the code link , REFER VIDEO( lowest common anscestor in binary tree)

#2

Hey @shashank_sabharwal
Refer to https://ide.codingblocks.com/s/347424?_ga=2.213840020.1250786384.1610781386-1795954092.1597348154

Just add two booleans as well as tunr them to true if a/b are found
Then in main if any one of them is false then that means its not present

#3

BUT the according to the method explained inthe video we were not checking that b is present or not for a particular case, in which prateek sir said we are just returning if a is present , then how to check in that case that is there is b or not

#4

Keep two booleans say X and Y and keep them false
when u find a then mark X as true
when u find b tthen mark Y as true

So instead of this

if(root->data == a || root->data == b){
return root;
}
use

 if(root->data == a ){
        X=true;
        return root;
    }
  if( root->data == b){
    Y=true;
return root;
}

Now when u come back to main after callin lca function
if X & Y ==false then that means either a is absent or b is absent or both are absent