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 String convert(String s, int nRows) { if(s == null || s.length()==0 || nRows <=0) return ""; if(nRows == 1) return s; StringBuilder res = new StringBuilder(); int size = 2*nRows-2; for(int i=0;i<nRows;i++) { for(int j=i;j<s.length();j+=size) { res.append(s.charAt(j)); if(i!=0 && i!=nRows-1 && j+size-2*i<s.length()) res.append(s.charAt(j+size-2*i)); } } return res.toString(); }