#include <stdio.h>
#include <math.h>

#define  POWER_RULE  (double)6.0
DisplayParameters(double temps,double distance,double vitesse);

int    count,limit_count;
FILE   *file;

main()
    {
    double distance_terre_lune = 384402000; /* en metres */
    double vitesse_eloignement = 0.1;	    /* en metres par annee */
    double incr_t = 1000; /* en annees */
    double K,temps,distance,incr_dist;

    K = pow(distance_terre_lune, POWER_RULE)*vitesse_eloignement;
    printf("K: %e\n",K);
    temps = 0;
    distance = distance_terre_lune;
    file = fopen("moon.dat","w");
    count = 1;
    limit_count = 1000000 / incr_t;
    do {
	incr_dist = vitesse_eloignement * incr_t;
	distance -= incr_dist;
	vitesse_eloignement = K / pow(distance, POWER_RULE);
	temps -= incr_t;
	DisplayParameters(temps,distance,vitesse_eloignement);
	if (temps == -500000000) {
	    incr_t = incr_t / 10;
	    limit_count = 10000 / incr_t;
	    count = 1;
	    break;
	    }
	}
    while(1);
    do {
	incr_dist = vitesse_eloignement * incr_t;
	distance -= incr_dist;
	vitesse_eloignement = K / pow(distance, POWER_RULE);
	temps -= incr_t;
	DisplayParameters(temps,distance,vitesse_eloignement);
	if (temps == -548500000) {
	    incr_t = incr_t / 10;
	    limit_count = 100 / incr_t;
	    count = 1;
	    break;
	    }
	}
    while(1);
    do {
	incr_dist = vitesse_eloignement * incr_t;
	distance -= incr_dist;
	vitesse_eloignement = K / pow(distance, POWER_RULE);
	temps -= incr_t;
	DisplayParameters(temps,distance,vitesse_eloignement);
	if (temps == -548572000) {
	    incr_t = 1;
	    break;
	    }
	}
    while(1);
    do {
	incr_dist = vitesse_eloignement * incr_t;
	distance -= incr_dist;
	vitesse_eloignement = K / pow(distance, POWER_RULE);
	temps -= incr_t;
	fprintf(stderr,"Temps: %8.0f distance: %10.0f vitesse: %9.6f\n",temps,distance,vitesse_eloignement);
	fprintf(file,"Temps: %8.0f distance: %10.0f vitesse: %9.6f\n",temps,distance,vitesse_eloignement);
	if (distance < 0) break;
	}
    while(1);
    fclose(file);
    }



DisplayParameters(double temps,double distance,double vitesse)
    {
    if (count++ >= limit_count) {
	fprintf(stderr,"Temps: %8.0f distance: %10.0f vitesse: %9.6f\n",temps,distance,vitesse);
	fprintf(file,"Temps: %8.0f distance: %10.0f vitesse: %9.6f\n",temps,distance,vitesse);
	count = 1;
	}
    }