BFS

#include<bits/stdc++.h>
using  namespace  std;

#define endl     "\n"
#define ll       long long
#define PI       acos(-1.0)
#define test     cout<<"\n****\n"
#define LCM(a,b) ((a/__gcd(a,b))*b)
#define precise  fixed(cout);cout<<setprecision(12)
#define fast     ios_base :: sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)


#define MAX 100
vector<int> graph[MAX+10];
int distan[MAX+10];

void BFS(int root,int numNode){

    memset(distan,-1,sizeof(distan));
    distan[root] = 0;

    queue<int> que;
    que.push(root);

    while (!que.empty()){

        int parent = que.front();
        que.pop();
        for (int i=0;i<graph[parent].size();i++) {
            int child = graph[parent][i];
            if (distan[child]==-1){
                distan[child] = distan[parent] + 1;
                que.push(child);
            }
        }
    }

    for(int i=1;i<=numNode;i++){
        cout<<i<<"->"<<distan[i]<<endl;
    }

}

void ConnectedAmong(int numNode){

    for(int i=1;i<=numNode;i++){
        cout<<i<<"->";
        if(graph[i].size()==0){

            cout<<"NULL";
        } else {
            for (int j = 0; j < graph[i].size(); j++) {
                cout << graph[i][j] << " ";
            }
        }
        cout<<endl;
    }
}

int main(){

    int numNode,numEdge;
    cin>>numNode>>numEdge;

    for(int i=0;i<numEdge;i++){
        int node,edge;
        cin>>node>>edge;
        graph[node].push_back(edge);
    }

    cout<<"The graph is Connected among: \n";
    ConnectedAmong(numNode);
    cout<<endl;

    cout<<"Enter the root of your graph: ";
    int root;
    cin>>root;
    cout<<endl;
    cout<<"Distance of every node from root: \n";
    BFS(root,numNode);

}


*************************************************************************************
**************************************NSUPS******************************************
#include<bits/stdc++.h>
using  namespace  std;

#define endl     "\n"
#define ll       long long
#define PI       acos(-1.0)
#define test     cout<<"\n****\n"
#define LCM(a,b) ((a/__gcd(a,b))*b)
#define precise  fixed(cout);cout<<setprecision(20)
#define fast     ios_base :: sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)

const int N = 100;
vector <int> graph[ N ];
int dist[ N ]; // dist of every node from the source
void bfs(int source) {
    memset(dist, -1, sizeof(dist));
    queue <int> q;
    dist[source] = 0;
    q.push(source);
    while (!q.empty()) {
        int f = q.front();
        q.pop();
        for (int i = 0; i < graph[f].size(); i++) {
            int child = graph[f][i];
            if (dist[child] == -1) {
                dist[child] = dist[f] + 1;
                q.push(child);
            }
        }
    }
    for (int i = 1; i <= 10; i++) cout << dist[i] << endl;
}
int main() {

    graph[1].push_back(2);
    graph[1].push_back(4);
    graph[1].push_back(3);
    graph[2].push_back(6);
    graph[4].push_back(7);
    graph[3].push_back(7);
    graph[3].push_back(8);
    graph[6].push_back(10);
    graph[8].push_back(7);
    graph[7].push_back(9);
    graph[8].push_back(5);
    graph[10].push_back(9);
    graph[10].push_back(5);

    bfs(1);
    return 0;
}