leetCode练习(6)

题目：ZigZag Conversion

难度：easy

问题描述：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   NA P L S I I GY   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".

错误点：

1.字符串没有初始化，在调用System.out.println(s)时，会显示null;

2.边界没有注意， int chushu=numRows*2-2;没有考虑numRows=1的特殊情况；

代码如下：