【leetcode】1078. Occurrences After Bigram

题目如下：

Given words first and second, consider occurrences in some text of the form "first second third", where second comes immediately after first, and third comes immediately after second.

For each such occurrence, add "third" to the answer, and return the answer.

Example 1:

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

Example 2:

Input: text = "we will we will rock you", first = "we", second = "will"
Output: ["we","rock"]

Note:

1. 1 <= text.length <= 1000
2. text consists of space separated words, where each word consists of lowercase English letters.
3. 1 <= first.length, second.length <= 10
4. first and second consist of lowercase English letters.

解题思路：非常简单的题目，先把text分割成数组形式，然后遍历text，如果text[i] = first 并且text[i+1] = second，那么text[i+2]就是一个answer。

代码如下：

class Solution(object):
    def findOcurrences(self, text, first, second):
        """
        :type text: str
        :type first: str
        :type second: str
        :rtype: List[str]
        """
        text = text.split(' ')
        res = []
        for i in range(len(text) - 2):
            if text[i] == first and text[i+1] == second:
                res.append(text[i+2])
        return res