BFS

#include <iostream>
#include <vector>
#include <queue>
using namespace std;

void bfs(int start,
         vector<int> adj[],
         int N)
{
    vector<bool> visited(N, false);

    queue<int> q;

    visited[start] = true;
    q.push(start);

    while(!q.empty())
    {
        int node = q.front();
        q.pop();

        cout << node << " ";

        for(int neighbour : adj[node])
        {
            if(!visited[neighbour])
            {
                visited[neighbour] = true;

                q.push(neighbour);
            }
        }
    }
}

int main()
{
    int N, M;

    cout << "Enter Nodes and Edges: ";
    cin >> N >> M;

    vector<int> adj[N];

    cout << "Enter Edges:\n";

    for(int i = 0; i < M; i++)
    {
        int u, v;

        cin >> u >> v;

        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    int start;

    cout << "Enter Starting Node: ";
    cin >> start;

    cout << "BFS Traversal: ";

    bfs(start, adj, N);

    return 0;
}