#include<stdio.h>
#include<stdlib.h>

/*
 GT 1D sandpile plus own modifications
*/

void sgenrand();
double genrand();

main(int argc, char **argv)
{

  int Nsteps,L,plot,mode,seed;
  int i,j,istep,irand,ntopplesteps,ntopplemax,ntopplelast;
  int *h,*hprev,*topplestat,*tleft,*tright;
  int hsum,hmax;
  int istepprint=10000,firstprint=1;
  FILE *fp;

  if (argc < 6) {
    printf("Usage: sandpile_rand Nsteps L plot mode seed\n");
    printf("\n");
    printf("     mode: 0 Add grain randomly, 1 add in middle\n");
    exit(0);
  }

  sscanf(argv[1],"%d",&Nsteps);
  sscanf(argv[2],"%d",&L);
  sscanf(argv[3],"%d",&plot);
  sscanf(argv[4],"%d",&mode);
  sscanf(argv[5],"%d",&seed);
  
  printf("Args were %d %d %d %d\n",Nsteps,L,plot,mode);

  h=(int *) malloc(sizeof(int)*(L+2));
  hprev=(int *) malloc(sizeof(int)*(L+2));
  topplestat=(int *) malloc(sizeof(int)*L/2*(L+2));
  tleft=(int *) malloc(sizeof(int)*(L+2));
  tright=(int *) malloc(sizeof(int)*(L+2));

  sgenrand(seed);


  ntopplemax=0;
  for(i=1;i<=L+1;i++) {  h[i]=0; topplestat[i]=0; }
  for(istep=1;istep<=Nsteps;istep++) {
    if (mode==0) {		
      /* Add grain */
      irand=(int)(genrand()*L)+1; 
      h[irand]++;
    } else if (mode==1) {		
      /*  Add grain in middle only */
      irand=(int)(L/2); 
      h[irand]++;
    }

    for(i=1;i<=L+1;i++) hprev[i]=h[i];

    /****** Start of one toppling loop step *****/

    ntopplelast=1;
    /* Loop as long as anything can be toppled */
    ntopplesteps=0;
    while (ntopplelast>0) {

      /* Find grains to be toppled */
      for(i=1;i<=L;i++) {
	tright[i]=0;
	tleft[i]=0;
	if (h[i] - h[i+1] > 2) tright[i]=1;
	if (h[i] - h[i-1] > 2) tleft[i]=1;
	if (tright[i]==1 && tleft[i]==1) {
	  /* But if only 3 grains too much, choose */
	  /* topple direction at random */
	  if (h[i] - h[i+1]==3 && h[i] - h[i-1]==3) {
	    tright[i]=0; tleft[i]=0;
	    if (genrand()>=0.5) tright[i]=1;
	    else tleft[i]=1;
	  }
	}
	
      }
      /* Topple grains */
      ntopplelast=0;
      for(i=1;i<=L;i++) {
	if (tright[i] == 1) {
	  h[i]-=2;
	  h[i+1]++;
	  h[i+2]++;
	  ntopplelast+=2;
	}
	if (tleft[i] == 1) {
	  h[i]-=2;
	  h[i-1]++;
	  h[i-2]++;
	  ntopplelast+=2;
	}
	/* print i,h[i] */
      }
      h[0]=0; h[-1]=0;
      h[L+1]=0; h[L+2]=0;
      ntopplesteps+=ntopplelast;
    }

    /****** End of one toppling loop step *****/
    
    if (istep > L*L) {
      if (firstprint) {
	printf("*********** Now starting to collect statistics *********\n");
	firstprint=0;
      }

      /* Collect statistics of of how many grains were toppled during this step */
      if (ntopplesteps > L/2*(L+2)) {
	printf("Error: ntopple array size too small, ntopple %d\n",ntopplesteps);
	exit(1);
      }

      topplestat[ntopplesteps]++;
      if (ntopplesteps > ntopplemax) ntopplemax=ntopplesteps;

    }
    
    if (plot==1 || (istep%istepprint==0) ) {
      /* Reduce printing interval for long runs */

      if (istep > istepprint*100) istepprint=istepprint*10;
      /* Plot results (ascii graphics) */

      hmax=0; 
      for(i=1;i<=L;i++) {
	if (hprev[i] > hmax) hmax=hprev[i];	
      }
      for(i=hmax;i>=1;i--) {
	for(j=1;j<=L;j++) {
	  if (hprev[j]>=i) printf("X");
	  else printf(" ");
	}
	printf("\n");
      }
      for(i=1;i<=L/2;i++) printf("- ");
      printf("\n");


      hmax=0; hsum=0;
      for(i=1;i<=L;i++) {
	hsum+=h[i];
	if (h[i] > hmax) hmax=h[i];	
      }
      for(i=hmax;i>=1;i--) {
	for(j=1;j<=L;j++) {
	  if (h[j]>=i) printf("X");
	  else printf(" ");
	}
	printf("\n");
      }
      for(i=1;i<=L;i++) printf("-");
      printf("           nstep %d ntopple %d ntopplemax %d hsum %d\n\n\n",istep,ntopplesteps,ntopplemax,hsum);

      if (firstprint==0 && istep%(istepprint*10)==0) {
	fp=fopen("topplestat.dat","w");
	for(i=0;i<=ntopplemax+1;i+=2) fprintf(fp,"%d %d\n",i,topplestat[i]);
	fclose(fp);
      }


    }
  }

}



/* A C-program for MT19937: Real number version                */
/*   genrand() generates one pseudorandom real number (double) */
/* which is uniformly distributed on [0,1]-interval, for each  */
/* call. sgenrand(seed) set initial values to the working area */
/* of 624 words. Before genrand(), sgenrand(seed) must be      */
/* called once. (seed is any 32-bit integer except for 0).     */
/* Integer generator is obtained by modifying two lines.       */
/*   Coded by Takuji Nishimura, considering the suggestions by */
/* Topher Cooper and Marc Rieffel in July-Aug. 1997.           */

/* This library is free software; you can redistribute it and/or   */
/* modify it under the terms of the GNU Library General Public     */
/* License as published by the Free Software Foundation; either    */
/* version 2 of the License, or (at your option) any later         */
/* version.                                                        */
/* This library is distributed in the hope that it will be useful, */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of  */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.            */
/* See the GNU Library General Public License for more details.    */
/* You should have received a copy of the GNU Library General      */
/* Public License along with this library; if not, write to the    */
/* Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA   */ 
/* 02111-1307  USA                                                 */

/* Copyright (C) 1997 Makoto Matsumoto and Takuji Nishimura.       */
/* Any feedback is very welcome. For any question, comments,       */
/* see http://www.math.keio.ac.jp/matumoto/emt.html or email       */
/* matumoto@math.keio.ac.jp                                        */

#include<stdio.h> 

/* Period parameters */  
#define N 624
#define M 397
#define MATRIX_A 0x9908b0df   /* constant vector a */
#define UPPER_MASK 0x80000000 /* most significant w-r bits */
#define LOWER_MASK 0x7fffffff /* least significant r bits */

/* Tempering parameters */   
#define TEMPERING_MASK_B 0x9d2c5680
#define TEMPERING_MASK_C 0xefc60000
#define TEMPERING_SHIFT_U(y)  (y >> 11)
#define TEMPERING_SHIFT_S(y)  (y << 7)
#define TEMPERING_SHIFT_T(y)  (y << 15)
#define TEMPERING_SHIFT_L(y)  (y >> 18)

static unsigned long mt[N]; /* the array for the state vector  */
static int mti=N+1; /* mti==N+1 means mt[N] is not initialized */

/* initializing the array with a NONZERO seed */
void
sgenrand(seed)
    unsigned long seed;	
{
    /* setting initial seeds to mt[N] using         */
    /* the generator Line 25 of Table 1 in          */
    /* [KNUTH 1981, The Art of Computer Programming */
    /*    Vol. 2 (2nd Ed.), pp102]                  */
    mt[0]= seed & 0xffffffff;
    for (mti=1; mti<N; mti++)
        mt[mti] = (69069 * mt[mti-1]) & 0xffffffff;
}

double /* generating reals */
/* unsigned long */ /* for integer generation */
genrand()
{
    unsigned long y;
    static unsigned long mag01[2]={0x0, MATRIX_A};
    /* mag01[x] = x * MATRIX_A  for x=0,1 */

    if (mti >= N) { /* generate N words at one time */
        int kk;

        if (mti == N+1)   /* if sgenrand() has not been called, */
            sgenrand(4357); /* a default initial seed is used   */

        for (kk=0;kk<N-M;kk++) {
            y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
            mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1];
        }
        for (;kk<N-1;kk++) {
            y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
            mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1];
        }
        y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK);
        mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1];

        mti = 0;
    }
  
    y = mt[mti++];
    y ^= TEMPERING_SHIFT_U(y);
    y ^= TEMPERING_SHIFT_S(y) & TEMPERING_MASK_B;
    y ^= TEMPERING_SHIFT_T(y) & TEMPERING_MASK_C;
    y ^= TEMPERING_SHIFT_L(y);

    return ( (double)y / (unsigned long)0xffffffff ); /* reals */
    /* return y; */ /* for integer generation */
}