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
SOLUTION:
class Solution:
def convert(self, s: str, numRows: int) -> str:
n = len(s)
if numRows == 1:
return s
op = ""
for i in range(numRows):
curr = i
down = True
while curr < n:
op += s[curr]
if down:
if numRows - i - 1 > 0:
curr += 2 * (numRows - i - 1)
else:
curr += 2 * i
else:
if i > 0:
curr += 2 * i
else:
curr += 2 * (numRows - i - 1)
down = not down
return op
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