132 lines
3.7 KiB
Java
132 lines
3.7 KiB
Java
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import java.util.HashMap;
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import java.util.LinkedList;
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import java.util.Map;
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import java.util.Objects;
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/**
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* @author wayne
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*/
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public class ACAutoMata {
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private ACNode root;
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public ACAutoMata() {
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this.root = new ACNode("/");
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}
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private void insert (String pattern) {
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ACNode node = this.root;
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int len = pattern.length();
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for (int i = 0; i < len; i++) {
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String c = pattern.charAt(i) + "";
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if(Objects.isNull(node.children.get(c))) {
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node.children.put(c, new ACNode(c));
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}
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node = node.children.get(c);
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}
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node.isEndingChar = true;
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node.length = pattern.length();
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}
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private void buildFailurePointer() {
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ACNode root = this.root;
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LinkedList<ACNode> queue = new LinkedList<>();
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queue.add(root);
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while (!queue.isEmpty()) {
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ACNode p = queue.pop();
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for(ACNode pc: p.children.values()){
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if (Objects.isNull(pc)) {
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continue;
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}
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if(p == root) {
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pc.fail = root;
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} else {
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ACNode q = p.fail;
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while (Objects.nonNull(q)) {
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ACNode qc = q.children.get(pc.data);
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if(Objects.nonNull(qc)) {
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pc.fail = qc;
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break;
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}
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q = q.fail;
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}
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if(Objects.isNull(q)) {
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pc.fail = root;
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}
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}
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queue.add(pc);
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}
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}
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}
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private Boolean match (String text) {
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ACNode root = this.root;
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ACNode p = root;
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int n = text.length();
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for(int i = 0; i < n; i++) {
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String c = text.charAt(i) + "";
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while(Objects.isNull(p.children.get(c)) && p != root){
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p = p.fail;
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}
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p = p.children.get(c);
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if(Objects.isNull(p)) {
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p = root;
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}
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ACNode tmp = p;
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while ( tmp != root) {
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if (tmp.isEndingChar == true) {
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System.out.println("Start from " + (i - p.length + 1));
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return true;
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}
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tmp = tmp.fail;
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}
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}
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return false;
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}
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public static boolean match(String text, String[] patterns) {
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ACAutoMata automata = new ACAutoMata();
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for (String pattern: patterns) {
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automata.insert(pattern);
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}
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automata.buildFailurePointer();
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return automata.match(text);
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}
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public class ACNode {
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private String data;
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private Map<String, ACNode> children;
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private Boolean isEndingChar;
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private Integer length;
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private ACNode fail;
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public ACNode(String data) {
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this.data = data;
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this.children = new HashMap<>();
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this.isEndingChar = false;
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this.length = 0;
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this.fail = null;
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}
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}
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public static void main(String[] args) {
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String[] patterns = {"at", "art", "oars", "soar"};
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String text = "soarsoars";
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System.out.println(match(text, patterns));
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String[] patterns2 = {"Fxtec Pro1", "谷歌Pixel"};
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String text2 = "一家总部位于伦敦的公司Fxtex在MWC上就推出了一款名为Fxtec Pro1的手机，该机最大的亮点就是采用了侧滑式全键盘设计。DxOMark年度总榜发布 华为P20 Pro/谷歌Pixel 3争冠";
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System.out.println(match(text2, patterns2));
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}
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}
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