careful about the divisor

ZigZag Conversion.cpp

class Solution {
public:
    string convert(string s, int nRows) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function    

       if(nRows<=1) return s; 
       int length=s.length(); 
       int numberItems=2*(nRows-1);
       int zones=length/numberItems+(length%numberItems==0? 0: 1);
       string result="";
           for(int row=0; row<nRows; row++)
           {
               for(int z=0; z<zones; z++)
               {
                   if(z*numberItems+row<length)
                   {
                       result+=s[z*numberItems+row];
                   }
                   if(row!=0 && row!=nRows-1 && (z+1)*numberItems-row<length)
                   {
                       result+=s[(z+1)*numberItems-row];
                   }
               }

           }
       return result; 
    }
};

ZigZag Conversion.java

public class Solution {
    public String convert(String s, int nRows) {
        // Start typing your Java solution below
        // DO NOT write main() function
        int length=s.length();
        if(length<nRows || nRows==1) return s; 
        int numbers=2*(nRows-1); 
        int sections=(length%numbers==0? length/numbers: length/numbers+1); 
        StringBuffer sb=new StringBuffer(); 
        for(int i=0; i<nRows; i++)
        {
            for(int j=0; j<sections; j++)
            {
                if(i+numbers*j<length) sb.append(s.charAt(i+numbers*j));
                if(i>0 && i<nRows-1 && numbers*(j+1)-i<length )  sb.append(s.charAt(numbers*(j+1)-i));
            }
        }
        return sb.toString(); 
    }
}