LeetCode 6 Z字形变换

将字符串 "PAYPALISHIRING" 以Z字形排列成给定的行数：

P   A   H   N
A P L S I I G
Y   I   R

之后从左往右，逐行读取字符："PAHNAPLSIIGYIR"

实现一个将字符串进行指定行数变换的函数:

string convert(string s, int numRows);

示例 1:

输入: s = "PAYPALISHIRING", numRows = 3
输出: "PAHNAPLSIIGYIR"

示例 2:

输入: s = "PAYPALISHIRING", numRows = 4
输出: "PINALSIGYAHRPI"
解释:

P     I    N
A   L S  I G
Y A   H R
P     I

示例代码：

方法一：

#!/usr/bin/python3
import math
def convert(s, numRows):
    stringBuf =['']*numRows
    length = len(s)
    i = 0
    while i=1 and i 

方法二：

#!/usr/bin/python3
import math
def convert(s, numRows):
    if numRows == 1 or numRows >= len(s):
        return s
    L =['']*numRows
    index,step = 0,1
    for x in s:
        L[index] += x
        if index == 0:
            step = 1
        elif index == numRows - 1:
            step = -1
        index += step
    return ''.join(L)
print("input the string:")
str = input()
print("input the num of row:") 
num = int(input())
print(convert(str,num))