leetcode - Zigzag Conversion

https://leetcode.com/problems/zigzag-conversion/submissions/

 

class Solution {
    public String convert(String s, int numRows) {
        int group=(numRows-2)*2+2;
        if(numRows<2) group=numRows;
        String[] rowsStr =new String[numRows];
        for(int i=0;i<rowsStr.length;i++) rowsStr[i]="";
        String ans="";
        for(int i=0;i<s.length();i++){
            int now=i%group;
            if(now>=numRows)   rowsStr[numRows*2-now-2]+=s.charAt(i);
            else  rowsStr[now%numRows]+=s.charAt(i);
        }
        for(int i=0;i<rowsStr.length;i++) ans+=rowsStr[i];
        return ans;
    }
}