letter combinations of a phone number

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.

1 2	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.

Solution

public class  {
    public List<String> letterCombinations(String digits) {
        LinkedList<String> q = new LinkedList<String>();
        if(digits.length()==0) return q;
        String[] mapping = new String[] {"0", "1", "abc", "def", "ghi", "jkl", "mno", "pqrs", "tuv", "wxyz"};
        q.add("");
        for(int i=0; i<digits.length(); i++) {
            int m = digits.charAt(i) - '0';
            while(q.peek().length()==i) {
                String temp = q.remove();
                for(char next:mapping[m].toCharArray()) {
                    q.add(temp+next);
                }
            }
        }
        return q;
    }
}

letter combinations of a phone number

近期文章

近期评论

标签

热门

文章归档

分类目录

功能