# [Solved] 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)

## Question

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`

## Python Solution

```class Solution:
def convert(self, s: str, numRows: int) -> str:
if numRows==1:
return s
row = 0
step = 1
t=['']*numRows
for i in range(len(s)):
t[row]+=s[i]
if row==numRows-1:
step=-1
elif row==0:
step=1
row=row+step
return ''.join(t)```