1#include <stdio.h>
2#include <stdlib.h>
3#include <string.h>
4
5#define MAX_NODES 100
6
7typedef struct {
8    int id;
9    int p_id;
10} Node;
11
12typedef struct {
13    int id;
14    char type[10];
15} ResultNode;
16
17void classifyNodes(Node nodes[], int n, ResultNode result[]) {
18    int children[MAX_NODES] = {0};
19    int isRoot[MAX_NODES] = {0};
20
21    for (int i = 0; i < n; i++) {
22        if (nodes[i].p_id == -1) {
23            isRoot[nodes[i].id] = 1;
24            continue;
25        }
26        children[nodes[i].p_id]++;
27    }
28
29    for (int i = 0; i < n; i++) {
30        int id = nodes[i].id;
31        strcpy(result[i].type, "Leaf");
32        if (children[id] > 0) strcpy(result[i].type, "Inner");
33        if (isRoot[id]) strcpy(result[i].type, "Root");
34        result[i].id = id;
35    }
36}
37
38int main() {
39    Node nodes[] = {{1, -1}, {2, 1}, {3, 1}, {4, 2}, {5, 2}};
40    int n = 5;
41    ResultNode result[5];
42    classifyNodes(nodes, n, result);
43    for (int i = 0; i < n; i++) {
44        printf("%d %s\n", result[i].id, result[i].type);
45    }
46    return 0;
47}

1using System.Collections.Generic;

public class Node {
    public int Id, PId;
    public Node(int id, int pId) { Id = id; PId = pId; }
}

public class TreeNode {
    public static void ClassifyNodes(List<Node> nodes) {
        var isChild = new HashSet<int>();

        foreach (var node in nodes) {
            if (node.PId != -1) isChild.Add(node.PId);
        }

        foreach (var node in nodes) {
            if (node.PId == -1) {
                Console.WriteLine(node.Id + " Root");
            } else if (isChild.Contains(node.Id)) {
                Console.WriteLine(node.Id + " Inner");
            } else {
                Console.WriteLine(node.Id + " Leaf");
            }
        }
    }

    public static void Main() {
        List<Node> nodes = new List<Node> {
            new Node(1, -1), new Node(2, 1), new Node(3, 1), new Node(4, 2), new Node(5, 2)
        };
        ClassifyNodes(nodes);
    }
}