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4
votes
0answers
103 views

The Complexity of Properly Learning Decision Trees

Where does this paper prove the middle bullet point of its abstract? I have looked through that paper fairly thoroughly. There are three things I want to read how they're getting around. ...
8
votes
1answer
189 views

Canonical representation of Binary Decision Tree in Ptime?

I am wondering whether there may exist a way to give a sort of "normal form" for binary decision trees (BDT) in a tractable way. More precisely: a BDT is a tree with internal nodes labelled by ...
1
vote
1answer
98 views

Lower bound for finding repeated elements in sorted array

This is inspired by [1] (which still needs answers). What is the tight lower bound (or optimal algorithms) for the "finding repeated elements" problem: Given a sorted integer array of size $n$, ...
11
votes
2answers
233 views

What is the complexity of the equivalence problem for read-once decision trees?

A read-once decision tree is defined as follows: $True$ and $False$ are read-once decision trees. If $A$ and $B$ are read-once decision trees and $x$ is a variable not occurring in $A$ and $B$, ...
7
votes
1answer
190 views

What is the complexity of decision tree complexity?

Given a boolean function $f$ on $n$ bits, how hard is it to determine its decision tree complexity? (I assume the decision tree is simple, i.e., the allowed questions are the bits of the input.) If ...
13
votes
0answers
314 views

How can one find the “hard” probability distribution on the input for recursive boolean functions?

Update: Since, it seems there is no progress regarding this question, any idea, conjecture, hunch, or advice is welcome. For example, are there any partial or incomplete results? What are the main ...
23
votes
1answer
401 views

The randomized query complexity of the conjoined trees problem

An important 2003 paper by Childs et al. introduced the "conjoined trees problem": a problem admitting an exponential quantum speedup that's unlike just about any other such problem that we know of. ...
13
votes
2answers
437 views

Las Vegas vs Monte Carlo randomized decision tree complexity

Background: Decision tree complexity or query complexity is a simple model of computation defined as follows. Let $f:\{0,1\}^n\to \{0,1\}$ be a Boolean function. The deterministic query complexity of ...
13
votes
2answers
405 views

Provable gaps between decision tree complexity and “true” complexity

The title is a little misleading: but hopefully the question isn't: Grønlund and Pettie's new result showing that 3SUM has only $O(n^{3/2})$ decision tree complexity got me wondering: Is there a ...
2
votes
0answers
39 views

How hard is it to compute an approximately optimal non-greedy CART tree?

The question itself is closer to the bottom of this post, and is formulated without any rerefence to the term "CART". Motivation: In traditional CART (Classification and Regression Trees), one ...
-1
votes
1answer
630 views

Time complexity analysis of random forest and k-means?

I am working with random forest for a supervised classification problem, and I am using the k-means clustering algorithm to split the data at each node, where $n$ is the number of points, $K$ is ...
18
votes
3answers
800 views

Sorting using a black box

Assume that we want to sort a list $S$ of $n$ real numbers. Assume that we are given a black box that can sort $\sqrt n$ real numbers instantly. How much advantage can we gain using this black box? ...
3
votes
0answers
227 views

Is there a tight lower bound on the complexity of SSSP on a graph?

I'm an undergrad and I'm not sure if this is the right way to ask this question. I want to know the lower bound on single-source shortest path computation in a general graph. The graph is allowed to ...
-2
votes
1answer
236 views

Sorting : proof for lower bound of Sorting [closed]

I have read the proof of lower bound of Sorting Algorithm that use comparison to know input is NlogN. In this paper, the author use decision tree for this proof. Everything on this proof I have ...
26
votes
1answer
773 views

Coloring complexity of graphs

Suppose $G$ is a graph with coloring number $d = \chi(G)$. Consider the following game between Alice and Bob. At each round, Alice picks a vertex, and Bob answers with a color in $\{1,\ldots,d-1\}$ ...
6
votes
0answers
202 views

Tree rotation, a problem similar to Huffman coding

I am not sure whether the following problem has been studied. We have a undirected tree $T$. We would like to construct another tree $T'$. $T'$ is a binary tree. Each inner nodes of $T'$ ...
6
votes
1answer
186 views

Is there an accepted name for Ross Quinlan's adaptation of the ID3 decision algorithm to use a Pearson's chi-squared test for independence?

In Ross Quinlan's seminal paper Induction of Decision Trees, Quinlan summarizes the current state of machine learning in 1985 and loudly introduces the ID3 decision algorithm in the context of its ...
0
votes
0answers
89 views

Designing an appropriate training set for CART classification using imbalanced data

I'm experimenting with using CART (or maybe Random Forest) to classify genomic data. There are essentially two classes, whereof one is the 'normal' state and the other is the 'exceptional' state. ...
13
votes
1answer
702 views

Algorithm for optimizing decision trees

Background A binary decision tree $T$ is a rooted tree where each internal node (and root) is labeled by an index $j \in \{1,..., n\}$ such that no path from root to leaf repeats an index, the leafs ...
2
votes
2answers
237 views

Building a decision tree to approximate a known function (not to learn an unknown function)

I have a function $f: \mathbb{D} \rightarrow \{0,1\}$ where $\mathbb{D} \in \mathbb{R}^{5000}$. I would like to approximate $f$ using a decision tree. Up to now I have only found literature in the ...
3
votes
1answer
288 views

Bounds on the size of smallest decision tree for a boolean function?

Consider a boolean function $f : V \rightarrow \{0,1\}$ with $m$ true points. Are there any non-trivial bounds in $m$ on the size of the smallest decision tree for $f$? It seems to me that assuming ...
0
votes
2answers
266 views

Learning using decision trees

I have a quick question that I'm stumped on. This is about constructing a decision tree using information gain (entropy). Let's say we have a dataset with two input attributes such that the ...