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 class Solution { public String convert(String s, int numRows) { int pStr = 0; String ret = ""; String[] graph = new String[numRows]; for(int i = 0; i < numRows; i++){ graph[i] = ""; } while(pStr < s.length()){ for(int i = 0; i < numRows; i++){ graph[i] += s.charAt(pStr++); if(pStr >= s.length()) break; } if(pStr >= s.length()) break; for(int i = numRows-2; i > 0; i--){ //even column, 2 element shorter than the odd column, fill from bottom to top graph[i] += s.charAt(pStr++); if(pStr >= s.length()) break; } } for(int i = 0; i < numRows; i++){ ret += graph[i]; } return ret; } }
原文：http://www.cnblogs.com/qionglouyuyu/p/5483347.html