/* Driver for routine eclazz */

#include <stdio.h>
#define NRANSI
#include "nr.h"
#include "nrutil.h"

#define N 15

int equiv(int i,int j)
{
	return (i % 4) == (j % 4);
}

int main(void)
{
	int i,j,k,lclas=0,nclass,*nf,*nflag,*nsav;

	nf=ivector(1,N);
	nflag=ivector(1,N);
	nsav=ivector(1,N);
	eclazz(nf,N,equiv);
	for (i=1;i<=N;i++) nflag[i]=1;
	printf("\nNumbers from 1-%d divided according to\n",N);
	printf("their value modulo 4:\n");
	for (i=1;i<=N;i++) {
		nclass=nf[i];
		if (nflag[nclass]) {
			nflag[nclass]=0;
			lclas++;
			k=0;
			for (j=i;j<=N;j++)
				if (nf[j] == nf[i]) nsav[++k]=j;
			printf("Class %2d:      ",lclas);
			for (j=1;j<=k;j++) printf("%3d",nsav[j]);
			printf("\n");
		}
	}
	free_ivector(nsav,1,N);
	free_ivector(nflag,1,N);
	free_ivector(nf,1,N);
	return 0;
}
#undef NRANSI