37 lines
891 B
Java
37 lines
891 B
Java
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import java.util.*;
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public class AhoCorasickSimple {
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static final int ALPHABET_SIZE = 26;
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String[] prefixes;
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public int[][] buildAutomata(String[] words) {
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Map<String, Integer> prefixMap = new TreeMap<>();
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for (String s : words) {
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for (int i = 0; i <= s.length(); i++) {
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prefixMap.put(s.substring(0, i), 0);
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}
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}
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prefixes = prefixMap.keySet().toArray(new String[0]);
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for (int i = 0; i < prefixes.length; i++) {
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prefixMap.put(prefixes[i], i);
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}
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int[][] transitions = new int[prefixes.length][ALPHABET_SIZE];
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for (int i = 0; i < prefixes.length; i++) {
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for (int j = 0; j < ALPHABET_SIZE; j++) {
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String s = prefixes[i] + (char) ('a' + j);
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while (!prefixMap.containsKey(s)) {
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s = s.substring(1);
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}
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transitions[i][j] = prefixMap.get(s);
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}
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}
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return transitions;
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}
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// Usage example
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public static void main(String[] args) {
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}
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}
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