[Leetcode]#6 ZigZag Conversion

//#6 ZigZag Conversion//108ms 4.86%class Solution {public:    string convert(string s, int numRows)     {        vector < vector<char> > v_v;        while(!s.empty())        {            vector<char> v(numRows, '0');            for(int i=0; i<numRows; i++)            {                if(!s.empty())                {                    v[i] = s[0];                    s.erase(s.begin());                }            }            v_v.push_back(v);            for(int i=0; i<numRows-2; i++)            {                if(!s.empty())                {                    vector<char> v(numRows, '0');                    v[numRows-i-2] = s[0];                    s.erase(s.begin());                    v_v.push_back(v);                }            }        }        string result;        for(int i=0; i<numRows; i++)        {            for(unsigned int j=0; j<v_v.size(); j++)            {                if(v_v[j][i] != '0')                {                    result.push_back(v_v[j][i]);                }            }        }        return result;    }};