描述
In English, we have a concept called root, which can be followed by some other word to form another longer word - let's call this word successor. For example, when the root "an" is followed by the successor word "other", we can form a new word "another".
Given a dictionary consisting of many roots and a sentence consisting of words separated by spaces, replace all the successors in the sentence with the root forming it. If a successor can be replaced by more than one root, replace it with the root that has the shortest length.
Return the sentence after the replacement.
Example 1:
Input: dictionary = ["cat","bat","rat"], sentence = "the cattle was rattled by the battery"
Output: "the cat was rat by the bat"
Example 2:
Input: dictionary = ["a","b","c"], sentence = "aadsfasf absbs bbab cadsfafs"
Output: "a a b c"
Example 3:
Input: dictionary = ["a", "aa", "aaa", "aaaa"], sentence = "a aa a aaaa aaa aaa aaa aaaaaa bbb baba ababa"
Output: "a a a a a a a a bbb baba a"
Example 4:
Input: dictionary = ["catt","cat","bat","rat"], sentence = "the cattle was rattled by the battery"
Output: "the cat was rat by the bat"
Example 5:
Input: dictionary = ["ac","ab"], sentence = "it is abnormal that this solution is accepted"
Output: "it is ab that this solution is ac"
Note:
- 1 <= dictionary.length <= 1000
- 1 <= dictionary[i].length <= 100
- dictionary[i] consists of only lower-case letters.
- 1 <= sentence.length <= 10^6
- sentence consists of only lower-case letters and spaces.
- The number of words in sentence is in the range [1, 1000]
- The length of each word in sentence is in the range [1, 1000]
- Each two consecutive words in sentence will be separated by exactly one space.
- sentence does not have leading or trailing spaces.
解析
根据题意，只需要先对 dictionary 按照长度从小到大进行排序，然后将 sentence 切分成词列表，对每个词进行判断，如果可以在 dictionary 中找到该词对应的词根 ，则将该词用词根替换掉，并将改词根追加到 res 中，否则就直接将该词追加到 res 中，等到遍历结束，将 res 拼接成字符串即可得到结果。
解答
class Solution(object):
def replaceWords(self, dictionary, sentence):
"""
:type dictionary: List[str]
:type sentence: str
:rtype: str
"""
dictionary = sorted(dictionary, key=lambda x:len(x))
res = []
for word in sentence.split(" "):
flag = True
for x in dictionary:
if len(x)<len(word) and word.startswith(x):
res.append(x)
flag = False
break
if flag:
res.append(word)
return " ".join(res).strip()
运行结果
Runtime: 268 ms, faster than 37.72% of Python online submissions for Replace Words.
Memory Usage: 22.8 MB, less than 67.07% of Python online submissions for Replace Words.
原题链接：leetcode.com/problems/re…
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