leetcode ZigZag Conversion 难度系数3 3.3

Question：

The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)

P   A   H   N
A P L S I I G
Y   I   R

And then read line by line: "PAHNAPLSIIGYIR"

Write the code that will take a string and make this conversion given a number of rows:

string convert(string text, int nRows);

convert("PAYPALISHIRING", 3) should return "PAHNAPLSIIGYIR".

public class Solution {
     public String convert(String s, int nRows) {
       if(s==null||s.length()<=1||nRows<=1){
    	   return s;
       }
       String[] results = new String[nRows];
       Arrays.fill(results, "");
       int MaxRowNumber = nRows-1;
       int n = 2*(MaxRowNumber);
       for(int i = 0;i<s.length();i++){
    	   results[MaxRowNumber-Math.abs((MaxRowNumber)-(i%n))] += s.charAt(i);
       }
       StringBuffer result = new StringBuffer();
       for(int i = 0;i<results.length;i++){
    	   result.append(results[i]);
       }
       return result.toString();
    }
}