-
Notifications
You must be signed in to change notification settings - Fork 13
/
BST_MinimumElementInBST.java
71 lines (60 loc) · 1.7 KB
/
BST_MinimumElementInBST.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
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.LinkedList;
import java.util.Queue;
// https://practice.geeksforgeeks.org/problems/minimum-element-in-bst/1/
// https://www.geeksforgeeks.org/find-the-minimum-element-in-a-binary-search-tree/
public class BST_MinimumElementInBST {
private static int minValue(Node root) {
int minVal = root.data;
while(root.left != null) {
minVal = root.left.data;
root = root.left;
}
return minVal;
}
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int t = Integer.parseInt(br.readLine().trim());
while(t-->0) {
String ip = br.readLine().trim();
Node root = buildTree(ip);
System.out.println(minValue(root));
}
}
private static Node buildTree(String str) {
if(str.length()==0 || str.charAt(0)=='N') return null;
String ip[] = str.split("\\s+");
Node root = new Node(Integer.parseInt(ip[0]));
Queue<Node> queue = new LinkedList<>();
queue.add(root);
int i = 1;
while(queue.isEmpty() && i < ip.length) {
Node currNode = queue.poll();
String currData = ip[i];
if(!currData.equals("N")) {
currNode.left = new Node(Integer.parseInt(currData));
queue.add(currNode.left);
}
i++;
if(i >= ip.length) break;
currData = ip[i];
if(!currData.equals("N")) {
currNode.right = new Node(Integer.parseInt(currData));
queue.add(currNode.right);
}
i++;
}
return root;
}
private static class Node {
private int data;
private Node left;
private Node right;
Node(int data) {
this.data = data;
left = right = null;
}
}
}