Description: Given a string s and a string array dictionary, return the longest string in the dictionary that can be formed by deleting some of the given string characters. If there is more than one possible result, return the longest word with the smallest lexicographical order. If there is no possible result, return the empty string.

Link: 524. Longest Word in Dictionary through Deleting

Examples:

Example 1:
Input: s = "abpcplea", dictionary = ["ale","apple","monkey","plea"]
Output: "apple"

Example 2:
Input: s = "abpcplea", dictionary = ["a","b","c"]
Output: "a"

Constraints:

    1 <= s.length <= 1000
    1 <= dictionary.length <= 1000
    1 <= dictionary[i].length <= 1000
    s and dictionary[i] consist of lowercase English letters.

思路: 返回最长的在字典中的单词，如果长度相同，按字母顺序最小的。所以先对字典中的单词排序，长度由大到小，字母顺序由小到大，然后遍历字典，是否单词是s的子串。

class Solution(object):
    def findLongestWord(self, s, dictionary):
        """
        :type s: str
        :type dictionary: List[str]
        :rtype: str
        """
        dictionary.sort(key=lambda x: (1000-len(x), x))
        for word in dictionary:
            if len(word) > len(s):
                continue
            i = 0
            for c in s:
                if i < len(word) and c == word[i]:
                    i += 1
            if i == len(word):
                return word
        return ''

 

日期: 2021-04-03