6. ZigZag Conversion

The string "Paypalishiring" is written with a zigzag pattern on a given number of rows like this: (You could want to display T His 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: "Pahnaplsiigyir"

Write the code that would 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

class Solution:    def convert(self, s, numRows):        """        :type s: str        :type numRows: int        :rtype: str        """        l = [‘‘ for _ in range(numRows)]        if numRows == 1:            return s        total = 2*(numRows-1)        for i in range(len(s)):            pos = i % total            if pos > numRows-1:                pos = total - pos            l[pos] += s[i]        res = ‘‘        for i in range(numRows):            res += l[i]        return res

There is no need to initialize the entire matrix, just initialize a one-dimensional list,l[i] to save the case of line I.

6. ZigZag Conversion