[Leetcode]6. ZigZag Conversion

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".

这个过程是两个循环组成的，向下循环numRows次，斜对角向上循环numRows-2次，重复下去，代码如下：

class Solution {public:    string convert(string s, int numRows) {        string str[numRows];        int i = 0, j = 0;        if (numRows == 1)            return s;        while (i < s.size())        {            for (int j = 0; j != numRows && i < s.size(); ++j)                str[j] += s[i++];            for (int j = numRows - 2; j != 0 && i < s.size() ; --j)                str[j] += s[i++];        }        string t;        for (int i = 0; i != numRows; ++i)            t += str[i];        return t;    }};