Sunday, October 9, 2016

Binary Tree Longest Consecutive Sequence

Given a binary tree, find the length of the longest consecutive sequence path.

The path refers to any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The longest consecutive path need to be from parent to child (cannot be the reverse).
For example,
   1
    \
     3
    / \
   2   4
        \
         5
Longest consecutive sequence path is 3-4-5, so return 3.
   2
    \
     3
    / 
   2    
  / 
 1
Longest consecutive sequence path is 2-3,not3-2-1, so return 2.


Use top-down approach would be easier. Parse the last value (parent value), current path and maximum path to each recursion. If lastVal + 1 = root.val, path++, otherwise path resets to 1. Maximum path is the maximum path of current path, left child path and right child path.


public int longestConsecutive(TreeNode root) {
        return getPath(root, root.val - 1, 0, 0);
    }

    private int getPath(TreeNode root, int lastVal, int path, int max) {
        if (root == null) {
            return 0;
        }
        path = lastVal + 1 == root.val ? path + 1 : 1;
        max = Math.max(max, path);
        int left = getPath(root.left, root.val, path, max);
        int right = getPath(root.right, root.val, path, max);
        return Math.max(max, Math.max(left, right));
    }


1 comment:

  1. The development of artificial intelligence (AI) has propelled more programming architects, information scientists, and different experts to investigate the plausibility of a vocation in machine learning. Notwithstanding, a few newcomers will in general spotlight a lot on hypothesis and insufficient on commonsense application. IEEE final year projects on machine learning In case you will succeed, you have to begin building machine learning projects in the near future.

    Projects assist you with improving your applied ML skills rapidly while allowing you to investigate an intriguing point. Furthermore, you can include projects into your portfolio, making it simpler to get a vocation, discover cool profession openings, and Final Year Project Centers in Chennai even arrange a more significant compensation.


    Data analytics is the study of dissecting crude data so as to make decisions about that data. Data analytics advances and procedures are generally utilized in business ventures to empower associations to settle on progressively Python Training in Chennai educated business choices. In the present worldwide commercial center, it isn't sufficient to assemble data and do the math; you should realize how to apply that data to genuine situations such that will affect conduct. In the program you will initially gain proficiency with the specialized skills, including R and Python dialects most usually utilized in data analytics programming and usage; Python Training in Chennai at that point center around the commonsense application, in view of genuine business issues in a scope of industry segments, for example, wellbeing, promoting and account.

    ReplyDelete