LeetCode 6 - ZigZag Conversion

原题如下：

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".

实现思路比较简单直白，直接上代码吧：

    public String convert(String s, int nRows) {
        int len = s.length();
        if(nRows >= len || nRows == 1){
            return s;
        }
        StringBuilder sb = new StringBuilder();
        for(int i =0; i< nRows; i++){
            int n = i;
            while(n<len){
                sb.append(s.charAt(n));
                if(i!=0 && i!= nRows-1){
                    n+=(nRows-i-1)<<1;
                    if(n<len){
                        sb.append(s.charAt(n));
                        n+=i<<1;
                    }
                }else{
                    n+=(nRows-1)<<1;
                }
            }
        }
        return sb.toString();
    }

参考源码：https://github.com/pkufork/Martians/blob/master/src/main/java/com/pkufork/martians/leetcode/L6_ZigZagConversion.java