题目:https://leetcode.com/problems/letter-combinations-of-a-phone-number/description/
代码:
class Solution {
public:
vector<string> letterCombinations(string digits) {
vector<string> res;
if(digits.size()==0) return res;
string m[10] = {"", "", "abc", "def", "ghi", "jkl", "mno", "pqrs", "tuv", "wxyz"};
res.push_back("");
for(int i =0;i<digits.size();i++){
vector<string> temp;
string t = m[digits[i]-'0'];
for(int j =0;j<t.size();j++)
for(int k=0;k<res.size();k++)
temp.push_back(res[k]+t[j]);
res = temp;
}
return res;
}
};