Stay button (leetcode 6) z conformal transformation python

topic

The number of a given string according to the given row, to down, left to right from the Z-shaped arrangement.

Example, the input string is the number of rows "LEETCODEISHIRING" is 3, arranged as follows:

LCIR
ETOESIIG
EDHN
After that, you need the output from left to right read line by line, produce a new string, such as: "LCIRETOESIIGEDHN".

You will realize this string conversion function specified number of lines:

string convert (string s, int numRows );
Example 1:

Input: s = "LEETCODEISHIRING", numRows = 3
Output: "LCIRETOESIIGEDHN"
Example 2:

Input: s = "LEETCODEISHIRING", numRows = 4
Output: "LDREOEIIECIHNTSG"
explanation:

L D R
E O E I I
E C I H N
T S G

Source: stay button (LeetCode)
link: https://leetcode-cn.com/problems/zigzag-conversion

Thinking

Directly open a list of two-dimensional simulation.

Code

class Solution:
    def convert(self, s: str, numRows: int) -> str:
        l=len(s)
        if l==1 or numRows==1:
            return s
        lie=l//(numRows*2-2)*(numRows-1)
        yu=l%(numRows*2-2)
        if yu<=numRows:
            lie+=1
        else:
            lie=lie +1 +yu-numRows
        ans=[['']*lie for _ in range(numRows)]
        i=0
        hang,x,y=0,0,0
        #print(ans)
        while(i<l):
            if hang<numRows:
                ans[hang][x]=s[i]
                hang+=1
                if hang==numRows:
                    x+=1
                    y=numRows-2
            elif  y!=0:
                ans[y][x]=s[i]
                y-=1
                x+=1
            if hang==numRows and y==0:
                hang=0
            i+=1
        res=""
        for ll in range(numRows):
            for hh in range(lie):
                if ans[ll][hh]!=' ':
                    res=res+ans[ll][hh]
        return res