-
Notifications
You must be signed in to change notification settings - Fork 2
/
LevelAverageBinaryTree.java
72 lines (61 loc) · 1.85 KB
/
LevelAverageBinaryTree.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
package Leetcode;
import java.util.ArrayList;
import java.util.Deque;
import java.util.LinkedList;
import java.util.List;
/**
* @author kalpak
*
* Given a non-empty binary tree, return the average value of the nodes on each level in the form of an array.
* Example 1:
* Input:
* 3
* / \
* 9 20
* / \
* 15 7
* Output: [3, 14.5, 11]
* Explanation:
* The average value of nodes on level 0 is 3, on level 1 is 14.5, and on level 2 is 11. Hence return [3, 14.5, 11].
* Note:
* The range of node's value is in the range of 32-bit signed integer.
*
*
*/
public class LevelAverageBinaryTree {
public static List<Double> averageOfLevels(TreeNode root) {
List<Double> result = new ArrayList<>();
Deque<TreeNode> queue = new LinkedList<>();
if(root == null)
return result;
queue.offer(root);
while(!queue.isEmpty()) {
int len = queue.size();
double average = 0;
int itr = 0;
while (itr < len) {
TreeNode current = queue.poll();
average += current.val;
if(current.left != null)
queue.offer(current.left);
if(current.right != null)
queue.offer(current.right);
itr++;
}
average /= len;
result.add(average);
}
return result;
}
public static void main(String[] args) {
TreeNode root = new TreeNode(12);
root.left = new TreeNode(7);
root.right = new TreeNode(1);
root.left.left = new TreeNode(9);
root.left.right = new TreeNode(2);
root.right.left = new TreeNode(10);
root.right.right = new TreeNode(5);
List<Double> result = averageOfLevels(root);
System.out.print("Level averages are: " + result);
}
}