Java开发联系人快速搜索程序_字符串匹配算法练习

public List<Contact> searchContacts(List<Contact> contacts, String keyword) {
    List<Contact> result = new ArrayList<>();
    String lowerKeyword = keyword.toLowerCase();
<pre class='brush:java;toolbar:false;'>for (Contact contact : contacts) {
    if (contact.getName().toLowerCase().contains(lowerKeyword) ||
        contact.getPhone().contains(keyword)) {
        result.add(contact);
    }
}
return result;

public int levenshteinDistance(String a, String b) {
    int[][] dp = new int[a.length() + 1][b.length() + 1];
<pre class='brush:java;toolbar:false;'>for (int i = 0; i <= a.length(); i++)
    dp[i][0] = i;
for (int j = 0; j <= b.length(); j++)
    dp[0][j] = j;

for (int i = 1; i <= a.length(); i++) {
    for (int j = 1; j <= b.length(); j++) {
        int cost = a.charAt(i - 1) == b.charAt(j - 1) ? 0 : 1;
        dp[i][j] = Math.min(Math.min(dp[i - 1][j] + 1,     // 删除
                     dp[i][j - 1] + 1),                   // 插入
                     dp[i - 1][j - 1] + cost);            // 替换
    }
}
return dp[a.length()][b.length()];

if (levenshteinDistance(contact.getName(), keyword) <= 2) {
    result.add(contact);
}

contacts.stream()
        .filter(c -> c.getName().toLowerCase().contains(keyword.toLowerCase()))
        .collect(Collectors.toList());