Hsort, heap sort

/* array of MAXARRAY length ... */
#define MAXARRAY 5

/* preform the heapsort */
void heapsort(int ar[], int len);
/* help heapsort() to bubble down starting at pos[ition] */
void heapbubble(int pos, int ar[], int len);

int main(void) {
int array[MAXARRAY];
int i = 0;

/* load some random values into the array */
for(i = 0; i < MAXARRAY; i++)
array[i] = rand() % 100;

/* print the original array */
printf("Before heapsort: ");
for(i = 0; i < MAXARRAY; i++)
{
printf(" %d ", array[i]);
}
printf("\n");

heapsort(array, MAXARRAY);

/* print the `heapsorted' array */
printf("After heapsort: ");
for(i = 0; i < MAXARRAY; i++)
{
printf(" %d ", array[i]);
}
printf("\n");

return 0;
}

void heapbubble(int pos, int array[], int len)
{
int z = 0;
int max = 0;
int tmp = 0;
int left = 0;
int right = 0;

z = pos;
for(;;) {
left = 2 * z + 1;
right = left + 1;

if(left >= len)
return;
else if(right >= len)
max = left;
else if(array[left] > array[right])
max = left;
else
max = right;

if(array[z] > array[max])
return;

tmp = array[z];
array[z] = array[max];
array[max] = tmp;
z = max;
}
}

void heapsort(int array[], int len)
{
int i = 0;
int tmp = 0;

for(i = len / 2; i >= 0; --i)
heapbubble(i, array, len);

for(i = len - 1; i > 0; i--)
{
tmp = array[0];
array[0] = array[i];
array[i] = tmp;
heapbubble(0, array, i);
}
}

Related Links :