java 116.在每个Node.java中填充下一个右指针

Posted 2021-05-08

/*Java solution with O(1) memory+ O(n) time*/
/**
 * Definition for binary tree with next pointer.
 * public class TreeLinkNode {
 *     int val;
 *     TreeLinkNode left, right, next;
 *     TreeLinkNode(int x) { val = x; }
 * }
 */
public class Solution {
    public void connect(TreeLinkNode root) {
        
        TreeLinkNode frontier = root;
        
        while(frontier != null){
            TreeLinkNode cur = frontier;
            while(cur != null){
                if(cur.left != null) cur.left.next = cur.right;
                if(cur.right != null && cur.next != null) cur.right.next = cur.next.left;
                cur = cur.next;
            }
            frontier = frontier.left;
        }
    }
}

/*BFS*/