String space substitution

Title Description

Write a method that replaces all spaces in the string with "%20". Assume that the string has enough space to hold the new characters, and that the true length of the string (less than or equal to 1000) is known, and that the string is made up of uppercase and lowercase letters.

Given a string inistring as the original string, and the length of the string int len, returns the replaced string.

Test examples:

"Mr John Smith" 13

return: "Mr%20john%20smith"

"Hello World  ", 12

return: "Hello%20%20world"

C + + Style solution

Method One: Use String::iterater it to traverse the entire string, and then (*it) "Switch to '%20 '

Method Two: Use String::find () to find the "" in the string, and then use String::replace () to "Switch to"%20 "

#include <fstream> #include <iostream>using namespace Std;class replacement_by_iterator {//Fayi: AC public:st    Ring Replacespace (string inistring, int length) {if (length<=0) return 0;    String strnew;    String::iterator it; For (It=inistring.begin (); It<=inistring.end (); it++) {if (*it== ')//Note single quote: Point to a single character strnew        + = "%20";         else strnew + = (*it);    } return strnew; }};class Replacement_by_replace {//Law II: acpublic:string replacespace (string inistring, int length) {Stri        ng strnew = inistring; while (Strnew.find (")! = Std::string::npos) {//npos:string class defines NPOs as guaranteed to be greater than any valid underlying value.          That is, the maximum size that the string class can hold Strnew.replace (Strnew.find (""), 1, "%20");    } return strnew; }};int Main (int argc, char** argv) {ifstream fin ("test.txt", Ios::in), if (Fin.fail ()) {cout << "File open failed" << Endl ; exit (-1);} Char ch;string teststring;while (fin.get (ch)) {teststring + = CH;} Fin.close ();  Replacement_by_iterator Replace1;   Law one replacement_by_replace replace2;    Law two cout << replace1.replacespace (teststring, Teststring.length ()) << Endl;        cout << replace2.replacespace (teststring, Teststring.length ()); return 0;}

String Space substitution