题目：
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".
思路：
我是通过找规律找到每一行应该取哪个字符。
package string; public class ZigZagConversion { public String convert(String s, int numRows) { if (s == null || numRows == 1) return s; int gap = 2 * (numRows - 1); int len = s.length(); StringBuilder sb = new StringBuilder(""); for (int i = 0; i < numRows; ++i) { for (int j = i; j < len; j += gap) { sb.append(s.charAt(j)); int next = j + 2 * (numRows - i - 1); if (i != 0 && i != numRows - 1 && next < len) sb.append(s.charAt(next)); } } return sb.toString(); } public static void main(String[] args) { // TODO Auto-generated method stub String s = "A"; ZigZagConversion z = new ZigZagConversion(); System.out.println(z.convert(s, 1)); } }