[LeetCode] Letter Combinations of a Phone Number

最新推荐文章于 2020-08-10 10:20:18 发布

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通过给定的数字字符串，实现将其转换为对应的字母组合，并详细解释了实现过程和使用的方法。

Given a digit string, return all possible letter combinations that the number could represent.

A mapping of digit to letters (just like on the telephone buttons) is given below.

Input:Digit string "23"
Output: ["ad", "ae", "af", "bd", "be", "bf", "cd", "ce", "cf"].

Note:

Although the above answer is in lexicographical order, your answer could be in any order you want.

class Solution {
public:
    vector<string> res;
    string path;
    string strT[10] = {"","","abc","def","ghi","jkl","mno","qprs","tuv","wxyz"};
    vector<string> letterCombinations(string digits) {
        dfs(digits,0);
        return res;
    }
    void dfs(string s,int dep){
        if(dep == s.size()){
            res.push_back(path);
            return;
        }
        int num = s[dep] - '0';
        string tmp = strT[num]; 
        for(int j = 0;j < tmp.size();j ++){
            path.push_back(tmp[j]);
            dfs(s,dep + 1);
            path.pop_back();
        }
    }
};