一、題目描述

請實現(xiàn)一個函數(shù)，將一個字符串中的每個空格替換成“%20”。例如，當字符串為We Are Happy.則經(jīng)過替換之后的字符串為We%20Are%20Happy。

二、代碼實現(xiàn)

方法一、書上的方法

# -*- coding:utf-8 -*-
class Solution:
    # s 源字符串
    def replaceSpace(self, s):
        # write code here
        spacenumber = 0
        for char in s:
            if char == ' ': spacenumber = spacenumber + 1
        result_len = len(s) + spacenumber * 3
        new_s = ['' for i in range(result_len)]
        for char in s[::-1]:
            if char == " ":
                new_s[result_len-2:result_len] = "%20"
                result_len = result_len - 3
            else:
                new_s[result_len-1] = char
                result_len = result_len - 1
        return ''.join(new_s)

方法二、python技巧

# -*- coding:utf-8 -*-
class Solution:
    # s 源字符串
    def replaceSpace(self, s):
        # write code here
        s = s.replace(" ", "%20")
        return s