gistfile1.java

class Solution {
public:
    string convert(string s, int nRows) {
        if(s.size()<=0) return s;
        if(nRows<=1) return s;
        
        string ret;
        
        for(int i=0; i<nRows; i++){
            for(int j=0, index=i; index<s.size(); j++, index = (2*nRows-2)*j+i){
                ret.append(1, s[index]);
                if(i==0 || i==nRows-1) continue;
                index = index + (nRows-i-1)*2;
                if(index<s.size())
                    ret.append(1, s[index]);
            }
        }
        return ret;
    }
};