替换空格

仅作为个人笔记

请实现一个函数，将一个字符串中的空格替换成“%20”。例如，当字符串为We Are Happy.则经过替换之后的字符串为We%20Are%20Happy。

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C++

class Solution {public:    void replaceSpace(char *str,int length) {        if(str == NULL && length <= 0)            return;        int originalLength = 0;        int numberOfBlank = 0;        int i = 0;        while(str[i] != '\0')        {            ++originalLength;            if(str[i] == ' ')                ++numberOfBlank;            ++i;        }        int newLength = originalLength + numberOfBlank * 2;        if(newLength > length)            return;        int indexOfOriginal = originalLength;        int indexOfNew = newLength;        while(indexOfOriginal >= 0 && indexOfNew > indexOfOriginal)        {            if(str[indexOfOriginal] == ' ')            {                str[indexOfNew--] = '0';                str[indexOfNew--] = '2';                str[indexOfNew--] = '%';            }            else            {                str[indexOfNew--] = str[indexOfOriginal];            }            --indexOfOriginal;        }    }};

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Java

public class Solution {    public String replaceSpace(StringBuffer str) {        if(str == null)            return null;        StringBuffer newStr = new StringBuffer();        for(int i = 0; i < str.length(); i++)        {            if(str.charAt(i) == ' ')            {                newStr.append('%');                newStr.append('2');                newStr.append('0');            }            else            {                newStr.append(str.charAt(i));            }        }        return newStr.toString();    }}

public class Solution {    public String replaceSpace(StringBuffer str) {        return str.toString().replaceAll("\\s", "%20");    }}

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Python

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

# -*- coding:utf-8 -*-class Solution:    # s 源字符串    def replaceSpace(self, s):        # write code here        index = range(len(s)-1,-1,-1)        for i in index:            if s[i].isspace():                s = s[:i] + "%20" + s[i+1:]        return s