LeetCode Letter Combinations of a Phone Number

链接：https://oj.leetcode.com/problems/letter-combinations-of-a-phone-number/

递归算法:

class Solution
{
    public:
        vector<string> letterCombinations(string digits)
        {
            vector<string> ans;
            string  table[]={"0","0","abc","def","ghi","jkl","mno","pqrs","tuv","wxyz"};
            dfs(digits,"",0,table,ans);
            return ans;

        }
        void dfs(string digits,string c,int offset,string table[],vector<string> &ans)
        {
            if(offset>=digits.length())
            {
                ans.push_back(c);
                return;
            }

            int pos=digits[offset]-'0';
            for(int i=0;i<table[pos].length();i++)
            {
                string tem=c;
                tem+=table[pos].at(i);
                dfs(digits,tem,offset+1,table,ans);
                tem.clear();
            }
        }

};