FlyingElephant's blog

Help in solving RTE

By FlyingElephant, history, 16 months ago, In English

I was solving this problem. But I keep getting RTE on test2 and I dont understand why.

My idea is selecting the smallest 2*n elements by putting them into a set. Then I use two pointers on the array sorted by coordinate component in order to get the system of nested segments. No wonder what goes wrong with that.

SUBMISSION

  • Vote: I like it
  • 0
  • Vote: I do not like it

Comments Comments (3)
| Write comment?
»
16 months ago, # |
  Vote: I like it +1 Vote: I do not like it

Let's analize this testcase:

1
1 3
1 -5
2 -6
3 -5

Your multiset will look like this s = {-6, -5}
For i = 0 and j = 2, both weights are -5, so you are going in the first if and erasing -5 and then trying to erase it again, but there was only one -5 in the multiset.

→ Reply
  • »
    »
    16 months ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    but wait.. in the multiset there must be 2 times -5. right?

    → Reply
    • »
      »
      »
      16 months ago, # ^ |
        Vote: I like it 0 Vote: I do not like it 
      if((ll) s.size() > 2*n){
	ll big = *(--s.end());
	s.erase(s.find(big));
}

      You are deleting the biggest value in multiset when it size is bigger than 2 * n, so no, there is only one -5 at the end in it.

      → Reply