Overview:
- The min heap created by the heapq.heapify() maintains the lowest element of the heap at the root.
- The heaprepalce() function of the Python heapq module pops the element at the root node and inserts an element into the min heap while maintaining the heap invariants.
Example:
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# Example Python program that pops an item and pushes another item # using heapq.heapreplace() function import heapq
# Construct a heap elems = [1, 7, 3, 5, 2, 11, 19, 17, 13] heapq.heapify(elems) print("The initial heap is:") print(elems)
print("Largest %d elements:"%len(elems)) sorted = heapq.nsmallest(len(elems), elems) print(sorted)
# pop and replace once heapq.heapreplace(elems, 23) print("After calling heapreplace once") print(elems)
# pop and replace again heapq.heapreplace(elems, 29) print("After calling heapreplace again") print(elems) |
Output:
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The initial heap is: [1, 2, 3, 5, 7, 11, 19, 17, 13] Largest 9 elements: [1, 2, 3, 5, 7, 11, 13, 17, 19] After calling heapreplace once [2, 5, 3, 13, 7, 11, 19, 17, 23] After calling heapreplace again [3, 5, 11, 13, 7, 29, 19, 17, 23] |