bfs(alg)adjecency mat

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




    int v,i,j,a,b,k=1,s;
    int p[100],d[2000000],clr[100];
    int adj[100][100],u;


 void BFS(int s)
 {


    for(i=1;i<=v;i++)
    {
        clr[i]=0;
        p[i]=-1;
        d[i]=0;
    }



    clr[s]=1;
    //p[s]=-1;
    queue<int> Q;

    Q.push(s);

    while(!Q.empty()){

        u=Q.front();
        Q.pop();

        for(i=1;i<=v;i++)
        {
            if(adj[u][i]==1 && clr[i]==0)
            {
                clr[i]=1;
                d[i]=d[u]+1;
                p[i]=u;
                Q.push(i);
            }
        }
        clr[u]=2;
    }

    cout<<"previous"<<endl;
 for(i=1;i<=v;i++)
 {
     cout<<p[i]<<" ";
 }
 cout<<endl;

     cout<<"cost"<<endl;
 for(i=1;i<=v;i++)
 {
     cout<<d[i]<<" ";
 }
  cout<<endl;

     cout<<"color"<<endl;
 for(i=1;i<=v;i++)
 {
     cout<<clr[i]<<" ";
 }





 }


int main()
{


    cout<<"vertex: ";
    cin>>v;

    do{

        cout<<"Edge"<<k<<":";
        cin>>  a >>  b  ;
        cout<<endl;

        if(a>v+1  || b>v+1)
        {
            cout<<"Input is invalid"<<endl;

        }
        else{

            adj[a][b]=1;

            adj[b][a]=1;



        }
           k++;

    }while(a!=0 && b!=0);




        for(i=1;i<=v;i++){

            int count=0;
            for(j=1;j<=v;j++)
            {

                cout<<adj[i][j]<<" ";



            }
            cout<<endl;
        }

cout<<"Enter source node"<<endl;
cin>>s;
if(s>v || s< 1)
    cout<<"invalid input"<<endl;
else
    BFS(s);


    return 0;

    }