#include "iostream.h"

void eclass(int nf[], int n, int lista[], int listb[], int m)
{
	int k,l,j;
    for (k = 1; k<=n; k++)
	{
        nf[k] = k;
    }
    for (l = 1; l<=m; l++)
	{
        j = lista[l];
        while (nf[j] != j)
		{
              j = nf[j];
        }
        k = listb[l];
        while (nf[k] != k)
		{
            k = nf[k];
        }
        if (j != k)
		{
			nf[j] = k;
		}
	}
    for (j = 1; j<=n; j++)
	{
        while (nf[j] != nf[nf[j]])
		{
            nf[j] = nf[nf[j]];
        }
    }
}

void main()
{
    //program d7r10
    //driver for routine eclass
    int i,j,n = 15; int m = 11;
    int lista[12], listb[12], nf[16], nflag[16], nsav[16];
    lista[1] = 1;  lista[2] = 1;  lista[3] = 5;   lista[4] = 2;
	lista[5] = 6;  lista[6] = 2;  lista[7] = 7;   lista[8] = 11;
	lista[9] = 3;  lista[10] = 4; lista[11] = 12;
    listb[1] = 5;  listb[2] = 9;  listb[3] = 13;  listb[4] = 6;
	listb[5] = 10; listb[6] = 14; listb[7] = 3;   listb[8] = 7;
	listb[9] = 15; listb[10] = 8; listb[11] = 4;
    eclass(nf, n, lista, listb, m);
	cout.setf(ios::right);
    for (i = 1; i<=n; i++)
	{
        nflag[i] = 1;
    }
    cout<<endl;
    cout<<"Numbers from 1-15 divided according to"<<endl;
    cout<<endl;
    cout<<"their value modulo 4:"<<endl;
    cout<<endl;
    int k,nclass,lclas = 0;
    for (i = 1; i<=n; i++)
	{
        nclass = nf[i];
        if (nflag[nclass] != 0)
		{
            nflag[nclass] = 0;
            lclas = lclas + 1;
            k = 0;
            for (j = 1; j<=n; j++)
			{
                if (nf[j] == nf[i])
				{
                    k = k + 1;
                    nsav[k] = j;
                }
            }
            cout<<"Class"<<lclas<<":"<<" ";   
            for (j = 1; j<=k; j++)
			{
				cout.width(4);
                cout<<nsav[j];
            }
            cout<<endl;
        }
    }
}