LeetCode : No6 ZigZag Conversion-优快云博客

本文介绍了一个LeetCode上的经典字符串操作题——Zigzag Conversion。通过分析题目要求，使用矩阵存储Z型排列的数据，并实现了字符串的转换。虽然此方法简单易懂，但效率较低。

题目链接：

https://leetcode.com/problems/zigzag-conversion/

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 text, int nRows);

convert("PAYPALISHIRING", 3) should return "PAHNAPLSIIGYIR".

题目很简单，于是我就用了最简单的矩阵来存储Z型数据，规律十分明显，不详述，很显然，该方法简单，但是效率也不高。

耗时：717ms。

class Solution:
    # @return a string
    def convert(self, s, nRows):
        if not s or nRows<=1:
            return s
        sList = []
        j = 0
        i = 0
        while (i<len(s)):
            Temp = ['']*nRows
            if j%(nRows-1) == 0:
                k=0
                while (k<nRows and i < len(s)):
                    Temp[k] = s[i]
                    k += 1
                    i += 1
            else:
                k = j%(nRows-1)
                Temp[-k-1] = s[i]
                i += 1
            sList.append(Temp)
            j += 1

        res = ''
        for i in range(len(sList[0])):
            for j in range(len(sList)):
                if sList[j][i]:
                    res += sList[j][i]
        return res