5

L、T、および A で構成される約 1,000 文字の文字列があります。そこには単純なパターンがあると確信しており、それを見つけるための迅速かつ簡単な方法があるかどうか疑問に思っています. この文字列は、これが 1 回限りではないように変更されます。

私が探しているパターンは、たとえば文字列が

LLLLLLLLAATAALLLLALLLLLLAATAALLLATLLLLLAATAALLAALLLLLAATAALL

部分文字列LLLLLAATAALLは、この文字列で 4 回繰り返されます。このような部分文字列を検索したいのですが、それらがどこで始まり、どこで終わり、いくつあるのか、そしてそれらが主な文字列にどれくらいの長さであるかがわかりません。

この種のものを探すためのJavaのツールがあれば、アドバイスをいただければ幸いです。

nt

4

2 に答える 2

4

わかりましたので、ここからコードを取得し、最も長く繰り返された部分文字列を追跡して出力するように調整しました。JUnit を使用して実行するだけです。

/* Copyright (c) 2010 the authors listed at the following URL, and/or
 the authors of referenced articles or incorporated external code:
 http://en.literateprograms.org/Suffix_tree_(Java)?action=history&offset=20100123220137

 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
 "Software"), to deal in the Software without restriction, including
 without limitation the rights to use, copy, modify, merge, publish,
 distribute, sublicense, and/or sell copies of the Software, and to
 permit persons to whom the Software is furnished to do so, subject to
 the following conditions:

 The above copyright notice and this permission notice shall be
 included in all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 Retrieved from: http://en.literateprograms.org/Suffix_tree_(Java)?oldid=16641
 */

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.junit.Test;

public class SuffixTree {
    @Test
    public void sampleUsage() {

        AbstractSuffixTree tree = new SimpleSuffixTree(
                "LLLLLLLLAATAALLLLALLLLLLAATAALLLATLLLLLAATAALLAALLLLLAATAALL");
        System.out.println("Longest repeating substring "
                + tree.best.printResult() + " repetitions=" + tree.best.visits
                + " length=" + tree.best.stringDepth);
    }
}

abstract class AbstractSuffixTree {

    SuffixTreeNode best;
    String text = null;
    SuffixTreeNode root = null;
    int inputAlphabetSize = -1;

    AbstractSuffixTree(String text) {
        if (text.length() > 0 && text.charAt(text.length() - 1) == '$') {
            this.text = text;
        } else {
            this.text = text + "$";
        }
    }

}

class SimpleSuffixTree extends AbstractSuffixTree {

    public SimpleSuffixTree(String text) {
        super(text);
        constructTree();
    }

    private void constructTree() {
        super.root = new SuffixTreeNode(this);
        best = root;
        char[] s = super.text.toCharArray();
        for (int i = 0; i < s.length; i++) {
            List<String> suffixList = new ArrayList<String>();
            for (int k = i; k < s.length; k++) {
                suffixList.add(s[k] + "");
            }
            super.root.addSuffix(suffixList, i + 1);
        }
    }

}

class CompactSuffixTree extends AbstractSuffixTree {

    public CompactSuffixTree(SimpleSuffixTree simpleSuffixTree) {
        super(simpleSuffixTree.text);
        super.root = compactNodes(simpleSuffixTree.root, 0);
        super.best = simpleSuffixTree.best;
    }

    private SuffixTreeNode compactNodes(SuffixTreeNode node, int nodeDepth) {
        node.nodeDepth = nodeDepth;
        for (SuffixTreeNode child : node.children) {
            while (child.children.size() == 1) {
                SuffixTreeNode grandchild = child.children.iterator().next();
                child.incomingEdge.label += ", "
                        + grandchild.incomingEdge.label;
                child.stringDepth += grandchild.incomingEdge.label.length();
                child.children = grandchild.children;
                // for (SuffixTreeNode grandchild : child.children)
                grandchild.parent = node;
            }
            child = compactNodes(child, nodeDepth + 1);
        }
        return node;
    }

}

class SuffixTreeNode {

    AbstractSuffixTree tree;
    SuffixTreeEdge incomingEdge = null;
    int nodeDepth = -1;
    int label = -1;
    Collection<SuffixTreeNode> children = null;
    SuffixTreeNode parent = null;
    int stringDepth;
    int id = 0;
    public static int c;
    public int visits = 1;

    public SuffixTreeNode(AbstractSuffixTree tree, SuffixTreeNode parent,
            String incomingLabel, int depth, int label, int id) {
        children = new ArrayList<SuffixTreeNode>();
        incomingEdge = new SuffixTreeEdge(incomingLabel, label);
        nodeDepth = depth;
        this.label = label;
        this.parent = parent;
        stringDepth = parent.stringDepth + incomingLabel.length();
        this.id = id;
        this.tree = tree;
    }

    public SuffixTreeNode(AbstractSuffixTree tree) {
        children = new ArrayList<SuffixTreeNode>();
        nodeDepth = 0;
        label = 0;
        this.tree = tree;
    }

    public void addSuffix(List<String> suffix, int pathIndex) {
        SuffixTreeNode insertAt = this;
        insertAt = search(this, suffix);
        insert(insertAt, suffix, pathIndex);
    }

    private SuffixTreeNode search(SuffixTreeNode startNode, List<String> suffix) {
        if (suffix.isEmpty()) {
            throw new IllegalArgumentException(
                    "Empty suffix. Probably no valid simple suffix tree exists for the input.");
        }
        Collection<SuffixTreeNode> children = startNode.children;
        for (SuffixTreeNode child : children) {
            if (child.incomingEdge.label.equals(suffix.get(0))) {
                suffix.remove(0);
                child.visits++;
                if (child.visits > 1
                        && child.stringDepth > tree.best.stringDepth) {
                    tree.best = child;
                }
                if (suffix.isEmpty()) {
                    return child;
                }
                return search(child, suffix);
            }
        }
        return startNode;
    }

    private void insert(SuffixTreeNode insertAt, List<String> suffix,
            int pathIndex) {
        for (String x : suffix) {
            SuffixTreeNode child = new SuffixTreeNode(tree, insertAt, x,
                    insertAt.nodeDepth + 1, pathIndex, id);
            insertAt.children.add(child);
            insertAt = child;
        }
    }

    public String toString() {
        StringBuilder result = new StringBuilder();
        String incomingLabel = this.isRoot() ? "" : this.incomingEdge.label;
        for (int i = 1; i <= this.nodeDepth; i++)
            result.append("\t");
        if (this.isRoot()) {
            c = 1;
            this.id = 1;
        } else {
            this.id = c;
            result.append(this.parent.id + " -> ");
            result.append(this.id + "[label=\"" + incomingLabel + "\"]" + "("
                    + visits + "," + (stringDepth) + ")" + ";\n");
        }
        for (SuffixTreeNode child : children) {
            c++;
            child.id = c;
            result.append(child.toString());
        }
        return result.toString();
    }

    public String printResult() {
        if (parent == null) {
            return "";
        } else {
            return this.parent.printResult() + this.incomingEdge.label;
        }
    }

    public boolean isRoot() {
        return this.parent == null;
    }

    public boolean isLeaf() {
        return children.size() == 0;
    }

}

class SuffixTreeEdge {

    String label = null;
    @SuppressWarnings("unused")
    private int branchIndex = -1;

    public SuffixTreeEdge(String label, int branchIndex) {
        this.label = label;
        this.branchIndex = branchIndex;
    }

}

出力：

最長繰り返し部分文字列 LLLLLLAATAALLL 繰り返し = 2 長さ = 14

編集：あなたのコメントへの応答。

現在、最も長く繰り返されている SuffixTreeNode (AbstractSuffixTree のフィールド) を追跡するだけです。これを変更して、stringDepth 順に並べられたノードの SortedQueue を追跡することができます。

于 2010-09-08T11:56:29.400 に答える
-1

次のコードから、文字列「hi」をカウントする方法についてのアイデアが得られます。

public int countHi(String str) {

int カウント = 0,i = str.length() - 1; 文字列の目標 = "こんにちは";

for(int j = 0;j < i;j++) { if(str.substring(j,j+2).equals(goal)) count++;} return count; }

于 2010-09-08T06:44:22.700 に答える