1#include <stdio.h>
2#include <stdlib.h>
3#include <stdbool.h>
4
5int dfs(int node, int** adjList, int* adjSize, bool* restricted, bool* visited) {
6    if (restricted[node] || visited[node]) return 0;
7    visited[node] = true;
8    int count = 1;
9    for (int i = 0; i < adjSize[node]; i++) {
10        count += dfs(adjList[node][i], adjList, adjSize, restricted, visited);
11    }
12    return count;
13}
14
15int reachableNodes(int n, int** edges, int edgesSize, int* edgesColSize, int* restricted, int restrictedSize) {
16    int** adjList = (int**)malloc(n * sizeof(int*));
17    int* adjSize = (int*)malloc(n * sizeof(int));
18    bool* restrictedSet = (bool*)calloc(n, sizeof(bool));
19    bool* visited = (bool*)calloc(n, sizeof(bool));
20    for (int i = 0; i < n; i++) {
21        adjList[i] = (int*)malloc(n * sizeof(int));
22        adjSize[i] = 0;
23    }
24
25    for (int i = 0; i < restrictedSize; i++) {
26        restrictedSet[restricted[i]] = true;
27    }
28
29    for (int i = 0; i < edgesSize; i++) {
30        int a = edges[i][0];
31        int b = edges[i][1];
32        adjList[a][adjSize[a]++] = b;
33        adjList[b][adjSize[b]++] = a;
34    }
35
36    int result = dfs(0, adjList, adjSize, restrictedSet, visited);
37
38    for (int i = 0; i < n; i++) {
39        free(adjList[i]);
40    }
41    free(adjList);
42    free(adjSize);
43    free(restrictedSet);
44    free(visited);
45
46    return result;
47}

1#include <vector>
#include <queue>
#include <unordered_set>
using namespace std;

int reachableNodes(int n, vector<vector<int>>& edges, vector<int>& restricted) {
    unordered_set<int> restrictedSet(restricted.begin(), restricted.end());
    vector<vector<int>> adjList(n);
    for (auto& edge : edges) {
        adjList[edge[0]].push_back(edge[1]);
        adjList[edge[1]].push_back(edge[0]);
    }
    queue<int> q;
    vector<bool> visited(n, false);
    q.push(0);
    visited[0] = true;
    int count = 0;
    while (!q.empty()) {
        int node = q.front(); q.pop();
        count++;
        for (int neighbor : adjList[node]) {
            if (!restrictedSet.count(neighbor) && !visited[neighbor]) {
                visited[neighbor] = true;
                q.push(neighbor);
            }
        }
    }
    return count;
}