标签：style blog http io ar color os sp for
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.
好长时间没练题了，最近比较懒加之工作略忙，疏于思考，浪费了很多时间。这题想来想去知道是要深搜，但是都没动手实现，以为很复杂，其实是很典型的DFS模板，这和 Sudoku solver 的思路基本没有差别（其实和所有类似的题型都没差，几乎都用DFS模板一套就能出来）
void comboIter(string digits, int i, vector<string> &domains, string cur, vector<string> &result) { if (i >= digits.size()) { result.push_back(cur); return; } char t = digits.at(i); string domain = domains[t-‘0‘]; string old = cur; for (char ele : domain) { cur += ele; comboIter(digits, i+1, domains, cur ,result); cur = old; } } vector<string> letterCombinations(string digits) { vector<string> ret; if (!digits.size()) return {""}; vector<string> domain = {"0","1","abc","def","ghi","jkl","mno","pqr","stu","vwxyz"}; comboIter(digits,0,domain,"",ret); return ret; }
[LeetCode] Letter Combinations of a Phone Number
标签：style blog http io ar color os sp for
原文地址：http://www.cnblogs.com/agentgamer/p/4156601.html
