package day0321.day0330;import java.util.HashSet;
import java.util.Set;public class JaccardSimilarity {public static double calculateJaccardSimilarity(String str1, String[] strArray) {// 将字符串视为字符的集合Set<Character> set1 = new HashSet<>();Set<Character> set2 = new HashSet<>();for (char c : str1.toCharArray()) {set1.add(c);}// 初始化最高相似度为0double maxSimilarity = 0;String mostSimilarString = "";// 遍历数组中的每个字符串，计算Jaccard相似度for (String str2 : strArray) {set2.clear(); // 清空set2，准备计算下一个字符串的集合for (char c : str2.toCharArray()) {set2.add(c);}// 计算交集Set<Character> intersection = new HashSet<>(set1);intersection.retainAll(set2);// 计算并集Set<Character> union = new HashSet<>(set1);union.addAll(set2);// 计算Jaccard相似度double jaccardSimilarity = (double) intersection.size() / union.size() * 0.7 + calculateCoefficient(str1.length(),str2.length()) * 0.3 ;// 更新最高相似度及相似字符串if (jaccardSimilarity > maxSimilarity) {maxSimilarity = jaccardSimilarity;mostSimilarString = str2;}}// 返回结果System.out.println("Jaccard Similarity: " + maxSimilarity);System.out.println("Most Similar String: " + mostSimilarString);return maxSimilarity;}public static double calculateCoefficient(int strLen, int strLen2) {// 直接使用差值的绝对值作为系数double coefficient = 1.0 / (1.0 + Math.abs(strLen - strLen2));return coefficient;}public static void main(String[] args) {// 示例用法String str1 = "BH44+ BH44";String[] strArray = { "BK54+BK55", "BH45+", "BH44+","BH44+BH45", "world"};double similarity = calculateJaccardSimilarity(str1, strArray);}
}