Q:
Given a string containing digits from 2-9 inclusive, 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. Note that 1 does not map to any letters.
Example:
Input: “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.
A:
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var letterCombinations = function(digits) {
var tmp = [" ", " ", "abc","def","ghi","jkl","mno","pqrs","tuv","wxyz"];
var ans = [];
var digitsArr = digits.split('');
var tmpArr = [];
for(item in digitsArr) {
tmpArr.push(tmp[digitsArr[item]])
}
if (tmpArr.length == 1) {
ans = tmpArr[0].split('');
return ans;
} else if (tmpArr.length < 1) {
return [];
}
ans = tmpArr[0];
for (var i = 0; i < tmpArr.length - 1; i++) {
ans = match(ans, tmpArr[i+1]);
}
function match(str1, str2) {
var group = [];
if(typeof str1 == 'string') {
arr1 = str1.split('');
} else {
arr1 = str1;
}
arr2 = str2.split('');
for (var m = 0; m < arr1.length; m++) {
for (var n = 0; n < arr2.length; n++) {
group.push(arr1[m] + arr2[n]);
}
}
return group;
}
return ans;
};
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