LeetCode1078-Bigram分词

题目链接

英文链接:https://leetcode.com/problems/occurrences-after-bigram/

中文链接:https://leetcode-cn.com/problems/occurrences-after-bigram/

题目详述

给出第一个词 first 和第二个词 second,考虑在某些文本 text 中可能以 “first second third” 形式出现的情况,其中 second 紧随 first 出现,third 紧随 second 出现。

对于每种这样的情况,将第三个词 “third” 添加到答案中,并返回答案。

示例 1:

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输入:text = "alice is a good girl she is a good student", first = "a", second = "good"
输出:["girl","student"]

示例 2:

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输入:text = "we will we will rock you", first = "we", second = "will"
输出:["we","rock"]

提示:

  1. 1 <= text.length <= 1000
  2. text 由一些用空格分隔的单词组成,每个单词都由小写英文字母组成
  3. 1 <= first.length, second.length <= 10
  4. first 和 second 由小写英文字母组成

题目详解

  • 首先对字符串进行分割,得到单词数组。
  • 然后遍历数组,判断是否满足条件,满足条件就加入结果集中。
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public class LeetCode_01078 {

public String[] findOcurrences(String text, String first, String second) {
String[] words = text.split(" ");
List<String> res = new ArrayList<>();
for (int i = 2; i < words.length; ++i) {
if (words[i - 2].equals(first) && words[i - 1].equals(second)) {
res.add(words[i]);
}
}
return res.toArray(new String[0]);
}
}