7.3: Inserting a value into the heap
- Page ID
- 49312
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A similar strategy exists for INSERT: just append the element to the array, then fixup the heap-invariants by swapping. For example if we just appended element N, then the only invariant violation possible involves that element, in particular if \(array[floor(N/2)]>array[N]\), then those two elements must be swapped and now the only invariant violation possible is between
array[floor(N/4)] and array[floor(N/2)]
we continue iterating until N=1 or until the invariant is satisfied.
INSERT(heap, element) append(heap.array, element) i = heap.array.length while (i > 1) { if (heap.array[i/2] <= heap.array[i]) break; swap(heap.array[i/2], heap.array[i]); i /= 2; }