Depth First Search Logical Error

[Rishav Paul]

#include<iostream>
using namespace std;

class dfs
{
         
             int v,i,matrix[20][20],j,color[20];
             
             public:
             dfs();
             void graph();
             void traversal(int);
};

dfs::dfs()
{
         for(int i=1;i<=20;i++)
         color[i]=0;
}

void dfs::graph()
{
     int e,s;
    cout<<"Enter the number of vertices\n";
    cin>>v;
    cout<<"Enter the number of edges\n";
    cin>>e;
    
    cout<<"Enter the edges\n";
    
    for(int k=1;k<=e;k++)
    {
     cin>>i>>j;
     matrix[i][j]=1;
    }
    
    cout<<"Enter the source vertex\n";
    cin>>s;
    
    traversal(s);
}  
void dfs::traversal(int s)
{   
    cout<<s<<" ";
    color[s]=1;

              for(j=1;j<=v;j++)
              if(matrix[s][j]==1&&color[j]==0)
              traversal(j);
}

int main()
{
    dfs a;
    a.graph();
    system("pause");
    return 0;
}

I am not getting the output for all inputs. Please help.

[Imadatobanisa]

What your correct output that you should have?

[Rishav Paul]

Enter the number of vertices
8
Enter the number of edges
9
Enter the edges
1 4
1 8
1 2
1 5
4 8
2 8
5 7
5 6
8 3
Enter the source vertex
1
1 2 8 3 Press any key to continue . . .

[Rishav Paul]

So I am not getting all the vertices visited. :(

[Imadatobanisa]

How did your output become '1 2 8 3'?

[Rishav Paul]

Hey 2 and 8 are adjacent to 1 and 3 is adjacent to 8.. program does not work after that..

[Rishav Paul]

Help please..