Example 1: python code for heap using heapify
class heap:
def maxheapify(self,array):
n=len(array)
for i in range(n//2-1,-1,-1):
self._maxheapify(array,n,i)
def _maxheapify(self,array,n,i):
l=2*i+1
r=2*i+2
if l<n and array[l]>array[i]:
largest=l
else:
largest=i
if r<n and array[r]>array[largest]:
largest=r
if (largest!=i):
array[largest],array[i]=array[i],array[largest]
self._maxheapify(array,n,largest)
def minheapify(self,array):
n = len(array)
for i in range(n//2-1,-1,-1):
self._minheapify(array,n,i)
def _minheapify(self,array,n,i):
l=2*i+1
r=2*i+2
if l<n and array[l]<array[i]:
smallest = l
else:
smallest = i
if r < n and array[r]<array[smallest]:
smallest = r
if (smallest != i):
array[smallest], array[i] = array[i], array[smallest]
self._minheapify(array, n, smallest)
def descending_heapsort(self,array):
n = len(array)
for i in range(n // 2 - 1, -1, -1):
self._minheapify(array, n, i)
for i in range(n - 1, 0, -1):
array[0], array[i] = array[i], array[0]
self._minheapify(array, i, 0)
def ascending_heapsort(self,array):
n=len(array)
for i in range(n//2-1,-1,-1):
self._maxheapify(array,n,i)
for i in range(n-1,0,-1):
array[0],array[i]=array[i],array[0]
self._maxheapify(array,i,0)
b=[550,4520,3,2340,12]
a=heap()
a.maxheapify(b)
print('Max Heapify -->',b)
a.minheapify(b)
print('Min Heapify -->',b)
a.ascending_heapsort(b)
print('Ascending Heap Sort -->',b)
a.descending_heapsort(b)
print('Descending Heap Sort -->',b)
Example 2: free function in python
PyObject *res;
char *buf = (char *) malloc(BUFSIZ); /* for I/O */
if (buf == NULL)
return PyErr_NoMemory();
...Do some I/O operation involving buf...
res = PyBytes_FromString(buf);
free(buf); /* malloc'ed */
return res;