ZigZag Conversion

这是一道让自己呵呵呵呵的题，到现在依然还是红红火火恍恍惚惚哼哼哈嘿。

当中这两个是关键点：

1. 

int size = 2*numRows - 2;

2.这个尤为不好懂，这个字符是紧接着size位置的字符（从行来看的话）

int temp = j + size - 2*i;

请参考： 点击打开链接，人家还是个妹子！！！

最后，即便都这样了，能不能不要犯下面的2个错误！！！

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

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".

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