<p>The string <code>&quot;PAYPALISHIRING&quot;</code> 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>

<pre>
P   A   H   N
A P L S I I G
Y   I   R
</pre>

<p>And then read line by line: <code>&quot;PAHNAPLSIIGYIR&quot;</code></p>

<p>Write the code that will take a string and make this conversion given a number of rows:</p>

<pre>
string convert(string s, int numRows);
</pre>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;PAYPALISHIRING&quot;, numRows = 3
<strong>Output:</strong> &quot;PAHNAPLSIIGYIR&quot;
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;PAYPALISHIRING&quot;, numRows = 4
<strong>Output:</strong> &quot;PINALSIGYAHRPI&quot;
<strong>Explanation:</strong>
P     I    N
A   L S  I G
Y A   H R
P     I
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> s = &quot;A&quot;, numRows = 1
<strong>Output:</strong> &quot;A&quot;
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= s.length &lt;= 1000</code></li>
	<li><code>s</code> consists of English letters (lower-case and upper-case), <code>&#39;,&#39;</code> and <code>&#39;.&#39;</code>.</li>
	<li><code>1 &lt;= numRows &lt;= 1000</code></li>
</ul>

class Solution:
    def convert(self, s: str, numRows: int) -> str:
        rows = [["_" for i in range(700)] for i in range(numRows)]
        
        characters = list(s)
        characters.reverse()
        
        currentColIndex = 0
        y = 0

        if numRows < 2:
            return s

        while(len(characters) > 0):
            if currentColIndex % (numRows-1) == 0 or currentColIndex == 0:
                # this is a full row
                self.add_this_col(currentColIndex, numRows, rows[0:numRows], s, characters)
                y = 0
            else:
                # add single element
                self.setElement(currentColIndex, (numRows-2) - y, rows, characters.pop())
                y += 1
            
            currentColIndex += 1
        
        result = ''
        for row in rows:
            for element in row:
                if element != "_":
                    result += element
        
        return result

    def add_this_col(self, colIndex: int, bottom: int, rows: List[str], s: str, queue: List[str]):
        for index in range(bottom):
            if len(queue) > 0:
                self.setElement(colIndex, index, rows, queue.pop())
            else:
                break
            
    def setElement(self, x, y, rows, value: str):
        rows[y][x] = value
        
    def getElement(self, x, y, rows):
        return rows[y][x]
            

22200