【leetcode】The problem of Zigzag pattern

题目描述

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) 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”.

优秀python代码分享

def convert(s, numRows): if numRows == 1 or numRows >= len(s): return s L = [''] * numRows index = 0 #index的使用十分巧妙 step = 1 for x in s: L[index] += x if index == 0: step = 1 elif index == numRows -1: step = -1 index += step return ''.join(L)