Graph Coloring

/*To implement graph colouring*/  
import java.io.*;  
class graph_colour  
{  
      void colournext(int k,int colour[],int n,int m,int edge[][])  
      {   
          int flag=0,j;  
          do  
          {  
             flag=0;  
         colour[k]=(colour[k]+1)%(m+1);  
         if(colour[k]==0)  
            return;  
         for(j=0;j<n;j++)  
         {   
                        if((edge[k][j]==1) && (colour[k]==colour[j]))  
            flag=1;  
         }  
           }while(flag==1);  
        }  
        public static void main(String args[]) throws IOException  
        {  
              int i,t,j,h,n,m,k,flag=0,maxclique=0;  
              System.out.println("Enter the no. of vertices in the graph");  
              BufferedReader br = new BufferedReader(new InputStreamReader(System.in));  
              n=Integer.parseInt(br.readLine());  
              graph_colour g=new graph_colour();  
              int edge[][]=new int[n][n];  
              int colour[]=new int[n];  
              for(i=0;i<n;i++)  
              colour[i]=0;  
              for(i=0;i<n;i++)  
              {   
                   for(j=0;j<n;j++)  
                   edge[i][j]=0;  
              }  
              for(i=0;i<n;i++)  
              {   
                   t=0;  
               System.out.println("enter number of adjacent nodes from node "+i);  
               t=Integer.parseInt(br.readLine());  
        if(t>maxclique)  
            maxclique=t;  
               System.out.println("enter those adjacent nodes");  
               for(j=0;j<t;j++)  
               {   
                               h=Integer.parseInt(br.readLine());  
                   edge[i][h]=1;  
               }  
               }  
               m=maxclique;  
               k=0;  
               do  
               {   
                  g.colournext(k,colour,n,m,edge);  
                  if(colour[k]==0)  
                   {k--;colour[k]=colour[k+1]%(m+1);}  
              else  
                     k++;  
           }  
               while( k<n);  
               System.out.println("\tnode\tcolor no.");  
               for(i=0;i<n;i++)  
               {  
                   System.out.println("\t"+i+"\t "+colour[i]);  
               }  
        }  
}