Description

Submission

class Solution {
    string arbitrate(string& a, string& b) {
        // a.length() >= b.length()
        int len = a.length() + b.length();
        string ret;
        for(int i = 0; i < len; ++i) {
            if(i % 2 == 0) ret.push_back(a[i>>1]);
            else ret.push_back(b[i>>1]);
        }

        return ret;
    }
public:
    string reformat(string s) {
        string nums, chars;

        for(char ch: s) {
            if(ch >= 'a' && ch <= 'z') chars.push_back(ch);
            else nums.push_back(ch);
        }

        if(nums.length() > chars.length() + 1 || chars.length() > nums.length() + 1) return "";

        if(nums.length() > chars.length()) return arbitrate(nums, chars);
        return arbitrate(chars, nums);
    }
};