string nLine(int LineIndex,string &s,int numRows){
string line;

int firstSkip,secondSkip;
firstSkip=2*(numRows-LineIndex)-3;
secondSkip=2*LineIndex-1;
line+=s[LineIndex];

for(int i=1,j=LineIndex;true;i++){
    j++;
    if(LineIndex==numRows-1)
        j+=secondSkip;
    else
        j+=firstSkip;
    if(j>=s.length())
        break;
    line+=s[j];
    j++;
    if(LineIndex==0)
        j+=firstSkip;
    else
        j+=secondSkip;
    if(j>=s.length())
        break;
    line+=s[j];

}

return line;
}

class Solution {
public:
    string convert(string s, int numRows) {
        if(numRows>s.length())
        numRows=s.length();
        if(numRows==1)
            return s;
        string ZigZag;
        if(s.length()==0)
            return "";
        for(int i=0;i<numRows;i++){

        ZigZag=ZigZag+nLine(i,s,numRows);

        }

    return ZigZag;
    }
};