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".

將字元進行Z字型轉換，然後進行儲存，一開始沒有想到什麼好方法，看了下別人的實現，可以做的比較簡單，每一行用一個字串記錄下來之後，然後拼接起來就可以，非滿列字串是有規律的，具體見下程式碼：

 class Solution {

 public:

     string convert(string s, int numRows) {

         vector<string> res;

         res.resize(numRows);

         string ret;

         int gap = numRows - ;

         int i = , j;

         while(i < s.size()){

             for(j = ; i < s.size() && j < numRows; ++i, ++j)

                 res[j] += s[i];

             for(j = gap; i < s.size() && j > ; ++i, --j)

                 res[j] += s[i];

         }

         for(int k = ; k < numRows; ++k){

             ret += res[k];

         }

         return ret;

     }

 };