Question / Problem: Leetcode

Solution

class Solution {
    int find(TreeNode root, int isLeft, int count){
        if(root == null) return count;
        if(isLeft == 1) 
            return Math.max(find(root.right,0,count+1), find(root.left,1,0));
        return Math.max(find(root.left,1,count+1), find(root.right,0,0));
    }
    public int longestZigZag(TreeNode root) {
        return Math.max(find(root.left,1,0), find(root.right,0,0));
    }
}

Algorithm

1. Current is left, and going to right then increment by 1 else reset to 0, Wiseversa

2. DP till to find the max between left and right possibility

3. return the Maximum integer

Readers

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