-
Notifications
You must be signed in to change notification settings - Fork 2
/
MinimumDepthOfBinaryTree.java
75 lines (61 loc) · 1.8 KB
/
MinimumDepthOfBinaryTree.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
73
74
75
package Leetcode;
import java.util.Deque;
import java.util.LinkedList;
/**
* @author kalpak
*
* Given a binary tree, find its minimum depth.
*
* The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.
*
* Note: A leaf is a node with no children.
*
* Example 1:
* Input: root = [3,9,20,null,null,15,7]
* Output: 2
*
* Example 2:
* Input: root = [2,null,3,null,4,null,5,null,6]
* Output: 5
*
* Constraints:
*
* The number of nodes in the tree is in the range [0, 105].
* -1000 <= Node.val <= 1000
*
*/
public class MinimumDepthOfBinaryTree {
public static int minDepth(TreeNode root) {
int result = 0;
Deque<TreeNode> queue = new LinkedList<>();
if(root == null)
return result;
queue.add(root);
while(!queue.isEmpty()) {
int len = queue.size();
result++;
while(len > 0) {
TreeNode current = queue.poll();
if(current.left == null && current.right == null)
return result;
if(current.left != null)
queue.offer(current.left);
if(current.right != null)
queue.offer(current.right);
len--;
}
}
return result;
}
public static void main(String[] args) {
TreeNode root = new TreeNode(12);
root.left = new TreeNode(7);
root.right = new TreeNode(1);
root.right.left = new TreeNode(10);
root.right.right = new TreeNode(5);
System.out.println("Tree Minimum Depth: " + minDepth(root));
root.left.left = new TreeNode(9);
root.right.left.left = new TreeNode(11);
System.out.println("Tree Minimum Depth: " + minDepth(root));
}
}