Heapifying a Min-Heap: Examining My Algorithm

[evinda]

Hello! (Wave)

I tried to write an algorithm that heapifies a min-heap..
That's what I have tried:

MIN_HEAPIFY(A,i){
  left=2*i;
  right=2*i+1;
  smallest=i;
  if (left<=length(A) and A[left]<A[smallest]) smallest=left;
  if (right<=length(A) and A[right]<A[smallest]) smallest=right;
  if (smallest!=i){
      swap(A[i],A[smallest]) ;
      MIN_HEAPIFY(A,i);
  }
}

Could you tell me if it is right? (Thinking)

 

[Future Bruno]

Yes, your algorithm looks correct. It is a recursive implementation of the min-heapify algorithm which takes an array A and an index i as parameters. The algorithm then compares the left and right children of the node at index i against the node itself and swaps them if they are smaller. If a swap occurs, the algorithm then recursively calls itself on the subtree rooted at the swapped node.