【Leetcode】1078. Occurrences After Bigram（第140周赛）（字符串处理）

àì夳堔傛蜴生んèń 2022-01-21 09:07 163阅读 0赞

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.

题目大意：

题目大意为给出前两个word，在字符串S中找出紧随其后的第三个word。

解题思路：

Python可以直接按照空格划分字符串。设置两个参数记录前两个word有没有被找到就行了。

class Solution:
        def findOcurrences(self, text: str, first: str, second: str) -> List[str]:
            tmp_t = text.split(' ')
            
            ans = []
            
            f = 0
            s = 0
            for i in tmp_t:
                if(f==1 and s==1):
                    ans.append(i)
                    if(i==first):
                        f=1
                        s=0
                    else:
                        f=0
                        s=0
                else:
                    if(f==0 and s==0 and first==i):
                        f=1
                    elif(f==1 and s==0 and second ==i):
                        s=1
                    else:
                        f=0
                        s=0
                        if(i==first):
                            f=1
            
            return ans;