Exemple #1
0
int main(){
	int i;

    /*Declare an integer n and assign it a value of 20.*/
	int n = 20;
    
    /*Allocate memory for an array of n integers using malloc.*/
	int *numbers = malloc(n * sizeof(int));
    
    /*Fill this array with random numbers, using rand().*/
	initializeSeed();

	for(i =0; i < n; i ++){
		numbers[i] = randomNumber(100);/*Will return a number from 0 to 99*/
	}

    /*Print the contents of the array.*/

	for(i = 0; i < n; i ++){
		printf("Contents of array[%d]: %d\n", i, numbers[i]);
	}

    /*Pass this array along with n to the sort() function of part a.*/

	sort(numbers,n);
    
    /*Print the contents of the array.*/

	for(i = 0; i < n; i ++){
			printf("Contents of sorted array[%d]: %d\n", i, numbers[i]);
	}

    return 0;
}
Exemple #2
0
BOOLEAN randomSchreier(
   PermGroup *const G,
   RandomSchreierOptions rOptions)
{
   Unsigned  noOfOriginalGens, successCount, level, finalLevel,
        nonInvolRejectCount, levelLowestOrder;
   unsigned long curOrder, lowestOrder;
   Permutation  **originalGen;
   FactoredInt  trueGroupOrder, factoredOrbLen;
   Permutation  *gen;
   Permutation  *randGen = newIdentityPerm( G->degree),
                *h = newUndefinedPerm( G->degree),
                *lowestOrderH = newUndefinedPerm( G->degree),
                *tempPerm;

   /* Set defaults for options. */
   if ( rOptions.initialSeed == 0 )
      rOptions.initialSeed = 47;
   if ( rOptions.minWordLengthIncrement == UNKNOWN )
      rOptions.minWordLengthIncrement = 7;
   if ( rOptions.maxWordLengthIncrement == UNKNOWN )
      rOptions.maxWordLengthIncrement = 23;
   if ( rOptions.stopAfter == UNKNOWN )
      if ( G->order )
         rOptions.stopAfter = 10000;
      else
         rOptions.stopAfter = 40;
   if ( rOptions.reduceGenOrder == UNKNOWN )
      rOptions.reduceGenOrder = TRUE;
   if ( rOptions.rejectNonInvols == UNKNOWN )
      rOptions.rejectNonInvols = 0;
   if ( rOptions.rejectHighOrder == UNKNOWN )
      rOptions.rejectHighOrder = 0;
   if ( rOptions.onlyEssentialInitGens == UNKNOWN )
      rOptions.onlyEssentialInitGens = FALSE;
   if ( rOptions.onlyEssentialAddedGens == UNKNOWN )
      rOptions.onlyEssentialAddedGens = TRUE;

   /* Initialize seed. */
   initializeSeed( rOptions.initialSeed);

  /* Check that fields of G that must be null initially actually are.  Then
     allocate these fields.  */
  if ( G->base || G->basicOrbLen || G->basicOrbit || G->schreierVec )
     ERROR( "randschr", "A group field that must be null initially was "
                        "nonnull.")
  G->base = allocIntArrayBaseSize();
  G->basicOrbLen = allocIntArrayBaseSize();
  G->basicOrbit = (UnsignedS **) allocPtrArrayBaseSize();
  G->schreierVec = (Permutation ***) allocPtrArrayBaseSize();

   /* If the true group order is known, set trueGroupOrder to it.  Otherwise
      allocate G->order and mark trueGroupOrder as undefined (i.e.,
      noOfFactors == UNKNOWN).  Then set G->order to 1.  */
      if ( G->order )
         trueGroupOrder = *G->order;
      else {
         G->order = allocFactoredInt();
         trueGroupOrder.noOfFactors = UNKNOWN;
      }
      G->order->noOfFactors = 0;

   /* Delete identity generators from G if present.  Return immediately if
      G is the identity group. */
   removeIdentityGens( G);
   if ( !G->generator) {     /* Should we allocate G->base, etc??? */
      G->baseSize = 0;
      return TRUE;
   }

   /* Adjoin an inverse image array to each permutation if absent. */
   adjoinGenInverses( G);

   /* Choose an initial segment of the base so that each generator moves
      some base point. */
   initializeBase( G);

   /* Here we allocate and construct an array of pointers to the original
      generators. */
   noOfOriginalGens = 0;
   originalGen = allocPtrArrayDegree();
   for ( gen = G->generator ; gen ; gen = gen->next )
      originalGen[++noOfOriginalGens] = gen;

   /* Fill in the level of each generator, and make each generator essential
      at its level and above. (????) */
   for ( gen = G->generator ; gen ; gen = gen->next ) {
      gen->level = levelIn( G, gen);
      MAKE_NOT_ESSENTIAL_ALL( gen);
      for ( level = 1 ; level <= gen->level ; ++level )
         MAKE_ESSENTIAL_AT_LEVEL( gen, level);
   }

   /* Construct the orbit length, basic orbit, and Schreier vector arrays.  Set
      G->order (previously allocated) to the product of the basic orbit
      lengths. */
   G->order->noOfFactors = 0;
   for ( level = 1 ; level <= G->baseSize ; ++level ) {
      G->basicOrbLen[level] = 1;
      G->basicOrbit[level] = allocIntArrayDegree();
      G->schreierVec[level] = allocPtrArrayDegree();
      if ( rOptions.onlyEssentialInitGens )
         constructBasicOrbit( G, level, "FindEssential");
      else
         constructBasicOrbit( G, level, "AllGensAtLevel" );
   }

   /* The variable successCount will count the number of consecutive times
      the quasi-random group element can be factored successfully. */
   successCount = 0;
   nonInvolRejectCount = 0;

   while ( successCount < rOptions.stopAfter &&
                  (trueGroupOrder.noOfFactors == UNKNOWN ||
                   !factEqual( G->order, &trueGroupOrder)) ) {

      randomizeGen( noOfOriginalGens, originalGen,
                    rOptions.minWordLengthIncrement,
                    rOptions.maxWordLengthIncrement, randGen);
      if ( factorGroupElt( G, randGen, h, &finalLevel) )
         ++successCount;
      else {
         successCount = 0;
         if ( rOptions.reduceGenOrder )
            replaceByPower( G, finalLevel, h);
         if ( nonInvolRejectCount >= rOptions.rejectNonInvols ||
                                                 isInvolution( h) ) {
            if ( nonInvolRejectCount > 0 &&
                 (lowestOrder < (curOrder = permOrder(h)) ||
                  lowestOrder == curOrder && levelLowestOrder > finalLevel) ) {
               tempPerm = h;  h = lowestOrderH;  lowestOrderH = tempPerm;
               finalLevel = levelLowestOrder;
            }
            if ( finalLevel == G->baseSize+1 ) {
               if ( G->baseSize >= options.maxBaseSize )
                  ERROR1i( "initializeBase",
                           "Base size exceeded maximum of ",
                            options.maxBaseSize, ".  Rerun with -mb option.")
               G->base[++G->baseSize] = pointMovedBy( h);
               G->basicOrbLen[G->baseSize] = 1;
               G->basicOrbit[G->baseSize] = allocIntArrayDegree();
               G->schreierVec[G->baseSize] = allocPtrArrayDegree();
            }
            assignGenName( G, h);
            addStrongGenerator( G, h, FALSE);
            h = newUndefinedPerm( G->degree);
            nonInvolRejectCount = 0;
         }
         else {
            curOrder = permOrder( h);
            if ( curOrder == 0 )
               curOrder = ULONG_MAX;
            if ( nonInvolRejectCount == 0 || curOrder < lowestOrder ||
                 (curOrder == lowestOrder && finalLevel > levelLowestOrder) ) {
               copyPermutation( h, lowestOrderH);
               lowestOrder = curOrder;
               levelLowestOrder = finalLevel;
            }
            ++nonInvolRejectCount;
         }
      }
   }

   freePtrArrayDegree( originalGen);
   deletePermutation( randGen);
   deletePermutation( h);
   deletePermutation( lowestOrderH);
   return  trueGroupOrder.noOfFactors != UNKNOWN &&
           factEqual( G->order, &trueGroupOrder);
}