-
Notifications
You must be signed in to change notification settings - Fork 1
/
nthPostorder.java
67 lines (51 loc) · 1.2 KB
/
nthPostorder.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
// print nth element when traverse a tree in post-order
import java.lang.Integer;
import java.lang.Math;
public class nthPostorder {
public static void main(String args[]) {
TreeNode root = new TreeNode(1);
TreeNode node1 = new TreeNode(-2);
TreeNode node2 = new TreeNode(-3);
root.left = node1;
root.right = node2;
TreeNode node3 = new TreeNode(1);
TreeNode node4 = new TreeNode(3);
TreeNode node5 = new TreeNode(-2);
node1.left = node3;
node1.right = node4;
node2.right = node5;
TreeNode node6 = new TreeNode(-1);
node3.left = node6;
TreeNode node7 = new TreeNode(0);
node6.right = node7;
Solution cl = new Solution();
System.out.println(cl.postorder(root, 7));
}
}
class TreeNode {
int val;
TreeNode left;
TreeNode right;
TreeNode(int x) { val = x; left = null; right = null;}
}
class Solution {
int count;
public int postorder(TreeNode root, int n) {
this.count = n;
int arr[] = {0};
recur(root, arr);
return arr[0];
}
private void recur(TreeNode node, int arr[]) {
if (null == node || 0 == this.count)
return;
recur(node.left, arr);
recur(node.right, arr);
this.count--;
if (0 == this.count) {
arr[0] = node.val;
return;
}
return;
}
}