fork download
copy 
  1. #include <iostream>
  2. using namespace std;
  3. #include <vector>
  4. #include <queue>
  5.  
  6. using namespace std;
  7.  
  8.  
  9.     // 1. Fixed the signature: Passed vis and adj by reference.
  10.     // Renamed 'V' to 'src' to avoid confusion with the total number of vertices.
  11.     void bfs(int src, vector<vector<int>> &adj, vector<int> &vis) {
  12.         vis[src] = 1;
  13.         queue<int> q;
  14.         q.push(src);
  15.  
  16.         while (!q.empty()) {
  17.             int v = q.front();
  18.             q.pop();
  19.             for (auto u : adj[v]) {
  20.                 if (vis[u] != 1) {
  21.                     vis[u] = 1;
  22.                     q.push(u);
  23.                 }
  24.             }
  25.         }
  26.     }
  27.     void dfs(int src, vector<vector<int>> &adj, vector<int> &vis){
  28.         vis[src] = 1;
  29.         for(auto &u : adj[src]){
  30.             if(vis[u] != 1){
  31.                 vis[u] = 1;
  32.                 dfs(u,adj,vis);
  33.             }
  34.         }
  35.     }
  36.  
  37.     int findNumberOfComponent(int V, vector<vector<int>> &edges) {
  38.         // 2. Used standard vector of vectors instead of a VLA
  39.         vector<vector<int>> adj(V);
  40.         vector<int> vis(V, 0); 
  41.  
  42.         // Build the adjacency list
  43.         for (int i = 0; i < edges.size(); i++) {
  44.             adj[edges[i][0]].push_back(edges[i][1]);
  45.             adj[edges[i][1]].push_back(edges[i][0]);
  46.         }
  47.  
  48.         int cnt = 0;
  49.         for (int i = 0; i < V; i++) {
  50.             if (!vis[i]) {
  51.                 cnt++;
  52.                 dfs(i, adj, vis);
  53.             }
  54.         }
  55.  
  56.         return cnt;
  57.     }
  58.  
  59. int main() {
  60.   int V = 4;
  61.     vector<vector<int>> edges = {
  62.         {0, 1},
  63.         {1, 2}
  64.     };
  65.     cout<<findNumberOfComponent(V,edges);
  66. }
Success #stdin #stdout 0.01s 5268KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
2
https://ideone.com/qh4mcz
language:
C++ (gcc 8.3)
created:
3 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!