Huffman coding

general
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1

I was trying to implement huffmann coding from here.

First code

Second code

Both codes are almost same and some changes are in lines 56-67. but the first one does’nt work and goes into infinite loop but the second one just works fine can somebody tell me why the first code is not working?

2

You are making node to point itself in first code, So when you call printCodes it will never end because of self loop.


       node* t=new node('$',0);
	while(pq.size()!=1)
	{
		t->l=pq.top();
		pq.pop();
		t->r=pq.top();
		pq.pop();
		t->p.first= t->l->p.first + t->r->p.first;
		pq.push(t);
	}

this snippet from your code. Say t is pointing to some address X. You are pushing the same address into priority_queue repeatedly. After some iterations X will point itself(X->l = X and X->r = X) but in code 2 you are creating new node at every step (no node will point itself)that’s why it’s working fine.

1 Like
3

Thanks @srikanth_16

4

pointers sucks -_-