enumerate-balanced-ideals/process.c

#include <stdio.h>
#include <string.h>
#include <sys/stat.h>

#include "thickenings.h"
#include "coxeter.h"
#include "queue.h"

int main(int argc, const char *argv[])
{
  FILE *infile;
  semisimple_type_t type;
  unsigned long left_invariance, right_invariance; // these are the invariances we have already modded out
  unsigned long left_invariant, right_invariant; // these are the invariances of the thickening under consideration
  int rank, cosets;
  node_t *graph;
  signed char *thickening;
  int *seen, *generators;
  queue_t queue;
  int ngenerators;
  int current;

  char string_buffer1[1000];
  const char *alphabet = "abcdefghijklmnopqrstuvwxyz";

  if(argc < 2)
    infile = stdin;
  else
    infile = fopen(argv[1], "rb");

  // we completely trust the input data
  ERROR(fread(&type.n, sizeof(int), 1, infile) == 0, "The input file seems to be empty!\n");
  type.factors = malloc(type.n * sizeof(simple_type_t));
  fread(type.factors, sizeof(simple_type_t), type.n, infile);
  fread(&left_invariance, sizeof(simple_type_t), type.n, infile);
  fread(&right_invariance, sizeof(simple_type_t), type.n, infile);

  rank = coxeter_rank(type);
  graph = graph_alloc(type);
  cosets = prepare_simplified_graph(type, left_invariance, right_invariance, graph);

  thickening = (signed char*)malloc(cosets*sizeof(signed char));
  generators = (int*)malloc(cosets*sizeof(int));
  seen = (int*)malloc(cosets*sizeof(int));

  while(fread(thickening, sizeof(signed char), cosets, infile) == cosets) {

    // determine invariances of this thickening
    left_invariant = right_invariant = -1; // set all bits to 1
    for(int j = 0; j < cosets; j++) {
      for(int k = 0; k < rank; k++) {
	if(thickening[j] > 0 && thickening[graph[j].left[k]] < 0 ||
	   thickening[j] < 0 && thickening[graph[j].left[k]] > 0)
	  left_invariant &= ~(1 << k);
	if(thickening[j] > 0 && thickening[graph[j].right[k]] < 0 ||
	   thickening[j] < 0 && thickening[graph[j].right[k]] > 0)
	  right_invariant &= ~(1 << k);
      }
    }

    // print this stuff
    printf("left: ");
    for(int j = 0; j < rank; j++)
      printf("%c", left_invariant & (1 << j) ? alphabet[j] : ' ');
    printf(" right: ");
    for(int j = 0; j < rank; j++)
      printf("%c", right_invariant & (1 << j) ? alphabet[j] : ' ');
    printf(" generators: ");

    // find a minimal set of weyl group elements such that the union of the ideals generated by their cosets wrt the invariances determined above gives the thickening
    // in the first step, mark everything which is equivalent to a "head" by a generator id
    ngenerators = 0;
    memset(generators, 0, cosets*sizeof(int));
    for(int j = 0; j < cosets; j++) {
      if(thickening[j] == HEAD_MARKER && generators[j] == 0) { // ignore the generator, if it is equivalent to one already seen
	ngenerators++;
	queue_init(&queue);
	queue_put(&queue, j);
	while((current = queue_get(&queue)) != -1) {
	  if(generators[current] == 0) { // visit everyone only once
	    generators[current] = ngenerators;
	    for(int k = 0; k < rank; k++) {
	      if(left_invariant & (1 << k))
		queue_put(&queue, graph[current].left[k]);
	      if(right_invariant & (1 << k))
		queue_put(&queue, graph[current].right[k]);
	    }
	  }
	}
      }
    }

    // in the second step, go through the list in ascending word length order and print the first appearance of each generator id
    memset(seen, 0, cosets*sizeof(int));
    for(int i = 0; i < cosets; i++) {
      if(generators[i] != 0 && seen[generators[i]-1] == 0) {
	seen[generators[i]-1] = 1;
	printf("%s ", alphabetize(graph[i].word, graph[i].wordlength, alphabet, string_buffer1));
      }
    }

    printf("\n");
  }

  if(infile != stdin)
    fclose(infile);

  graph_free(type, graph);
  free(type.factors);
  free(thickening);
}
  /*******************************************************************************************

  seen = (int*)malloc(order*sizeof(int));
  generators = (int*)malloc(order*sizeof(int));
  level = (signed char*)malloc(order*sizeof(int));

  graph = graph_alloc(type);
  prepare_graph(type, graph);

  // finally do stuff

  int counter = 0;

  while(fread(level, sizeof(signed char), order, infile) == order) {

    if((~left_invariant & left_invariant_wanted) == 0 && (~right_invariant & right_invariant_wanted) == 0) {
      ngens = 0;
      memset(generators, 0, order*sizeof(int));
      for(int j = 0; j < order; j++) {
	if(level[j] == HEAD_MARKER && generators[j] == 0) { // ignore the generator, if it is equivalent to one already seen
	  ngens++;
	  queue_init(&queue);
	  queue_put(&queue, j);
	  while((current = queue_get(&queue)) != -1) {
	    if(generators[current] == 0) { // visit everyone only once
	      generators[current] = ngens;
	      for(int k = 0; k < rank; k++) {
		if(left_invariant & (1 << k))
		queue_put(&queue, graph[current].left[k]);
		if(right_invariant & (1 << k))
		  queue_put(&queue, graph[current].right[k]);
	      }
	    }
	  }
	}
      }

      printf("left: ");
      for(int j = 0; j < rank; j++)
	printf("%c", left_invariant & (1 << j) ? alphabet[j] : ' ');
      printf(" right: ");
      for(int j = 0; j < rank; j++)
	printf("%c", right_invariant & (1 << j) ? alphabet[j] : ' ');
      printf(" generators: ");

      memset(seen, 0, order*sizeof(int));
      for(int i = 0; i < order; i++) {
	if(generators[i] != 0 && seen[generators[i]-1] == 0) {
	  seen[generators[i]-1] = 1;
	  //	if(type.n == 1 && type.factors[0].series == 'A')
	  //	  printf("%s ", stringify_SLn1_permutation(graph[i].word, graph[i].wordlength, rank, string_buffer1));
	  //	else if(type.n == 1 && (type.factors[0].series == 'B' || type.factors[0].series == 'C'))
	  //	  printf("%s ", stringify_Onn1_permutation(graph[i].word, graph[i].wordlength, rank, string_buffer1));
	  //	else
	  if(i == 0)
	    printf("1 ");
	  else
	    printf("%s ", alphabetize(graph[i].word, graph[i].wordlength, alphabet, string_buffer1));
	}
      }

      printf("\n");
    }
  }

  if(infile != stdin)
    fclose(infile);

  // cleanup

  graph_free(type, graph);
  free(seen);
  free(generators);
  free(type.factors);

  return 0;
}
*/