6\. Zigzag Conversion

Medium

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 s, int numRows); 

**Example 1:**

**Input:** s = "PAYPALISHIRING", numRows = 3

**Output:** "PAHNAPLSIIGYIR" 

**Example 2:**

**Input:** s = "PAYPALISHIRING", numRows = 4

**Output:** "PINALSIGYAHRPI"

**Explanation:** P I N A L S I G Y A H R P I 

**Example 3:**

**Input:** s = "A", numRows = 1

**Output:** "A" 

**Constraints:**

*   `1 <= s.length <= 1000`
*   `s` consists of English letters (lower-case and upper-case), `','` and `'.'`.
*   `1 <= numRows <= 1000`