code: https://ide.codingblocks.com/s/578321
problem: https://leetcode.com/problems/binary-tree-maximum-path-sum/
The code has been accepted but I had a doubt,
in line 34 if I do not add 0 in return max(0,max(op3,op4));
it is giving the wrong answer but why? because even if the path sum is negative in that subtree we have to return it right ? but here we are returning 0 instead
int op1 = root->value + left + right; // max path sum passes through the root
int op2 = root->value ;// left and right path sums are negative
int op3 = left + root->value ;
int op4 = right + root->value;
at line 34 basically u should return max(op2, max(op3,op4)) because for the above tree max ans could be this root itself or this root->val + ans from right subtree or root->val + ans from left subtree.
i am unable to understand why u are doing max with 0
thanks a lot makes sense now, earlier I was only returning left path sum and right path sum didn’t realise that the root can be returned too
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