Leetcode题解-500. Keyboard Row_leedcode 500题题解答案集合 python-优快云博客

本文链接：https://blog.youkuaiyun.com/hzw2945/article/details/78144591

本文介绍了解决LeetCode 500题的方法，该题要求从给定单词列表中找出仅使用美国键盘同一行字母组成的单词。通过创建三个字符集合分别对应键盘的三行，遍历输入的单词并检查它们的字符是否只出现在其中一个集合中。

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Leetcode题解-500. Keyboard Row

Given a List of words, return the words that can be typed using letters of alphabet on only one row’s of American keyboard like the image below.

American keyboard
这里写图片描述

Example 1:
Input: [“Hello”, “Alaska”, “Dad”, “Peace”]
Output: [“Alaska”, “Dad”]
Note:

You may use one character in the keyboard more than once.
You may assume the input string will only contain letters of alphabet.

思路

把键盘的三行建立三个集合，遍历每个字符串的字符，如果出现在不同的集合里就不符合条件。（这里大写键和Shift不纳入考虑）

代码

小细节：通过set.count()函数来判断字符是否在集合

vector<string> findWords(vector<string>& words) {
        vector<string> res;
        set<char> row1{'q','w','e','r','t','y','u','i','o','p'};
        set<char> row2{'a','s','d','f','g','h','j','k','l'};
        set<char> row3{'z','x','c','v','b','n','m'};
        for(string s : words){
            int first = 0, second = 0, third = 0;
            for(char c : s){
                if(c < 'a') c+=32;
                if(row1.count(c)) first = 1;
                if(row2.count(c)) second = 1;
                if(row3.count(c)) third = 1;
                if(first + second + third > 1) break;
            }
            if(first + second + third == 1) res.push_back(s);
        }
        return res;
    }