set.c

#include "error.h"

#include <assert.h>
#include <stdlib.h>

static int size = 0;

/* Set the set size */
void
SetSize(int n) {
  size = n + 1;
}

/* Allocate a new set */
char *
SetNew() {
  char *s;
  s = (char *)calloc((size_t)size, 1);
  MemoryCheck(s);
  return s;
}

/* Deallocate a set */
void
SetFree(char *s) {
  free(s);
}

/* Add a new element to the set.  Return TRUE if the element was added
 * and FALSE if it was already there.
 */
int
SetAdd(char *s, int e) {
  int rv;
  assert(e >= 0 && e < size);
  rv = s[e];
  s[e] = 1;
  return !rv;
}

/* Add every element of s2 to s1.  Return TRUE if s1 changes. */
int
SetUnion(char *s1, char *s2) {
  int i, progress;
  progress = 0;
  for (i = 0; i < size; i++) {
    if (s2[i] == 0)
      continue;
    if (s1[i] == 0) {
      progress = 1;
      s1[i] = 1;
    }
  }
  return progress;
}