leetcode 524. Longest Word in Dictionary through Deleting

本文介绍了一种算法，该算法通过从给定字符串中删除某些字符来形成字典中最长的单词。如果存在多个相同长度的单词，则返回字典序最小的一个。文章提供了具体的实现代码，包括对输入字符串和字典进行排序的方法，以便快速找到符合条件的最长单词。

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524. Longest Word in Dictionary through Deleting

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

Example 1:

Input:
s = "abpcplea", d = ["ale","apple","monkey","plea"]

Output: 
"apple"

Example 2:

Input:
s = "abpcplea", d = ["a","b","c"]

Output: 
"a"

Note:

All the strings in the input will only contain lower-case letters.
The size of the dictionary won't exceed 1,000.
The length of all the strings in the input won't exceed 1,000.

1、sort(, , compare) 这点很重要！

static bool compare(string a, string b)
{
    if (a.size() == b.size())
    {
        int k = 0;
        while (k < a.size() && k < b.size() && a[k] == b[k])
            k++;
        return a[k] < b[k];
    }
    return a.size() > b.size();
}

class Solution {
public:
    string findLongestWord(string s, vector<string>& d) 
    {
        sort(d.begin(), d.end(), compare);
        for (auto ss : d)
        {
            int i = 0, j = 0;
            while (i < s.size() && j < ss.size())
            {
                if (s[i] == ss[j])
                {
                    j++;
                }
                i++;
            }
            if (j == ss.size())
                return ss;
        }
        return "";
    }
};