Write a method to replace all spaces in a string with '%20'. You may assume that the string has sufficient space at the end of the string to hold the additional characters, and that you are given the "true" length of the string. (Note: if implementing in Java, please use a character array so you can perform this operation in place.) EXAMPLE Inpu…

CareerCup1.4.cpp

#include "stdafx.h"
#include <string>
#include <iostream>

void ReplaceSpace(std::string&);
int main()
{
  using namespace std;
  string str;
	getline(cin,str);
	//Find the number of ' ' and the end of meaningful chars
	ReplaceSpace(str);
	cout<<str<<endl;
	return 0;
}

void ReplaceSpace(std::string& str)
{
	int numofSpace=0;
	int endofchars=-1;
	bool meaningfulchar=false;
	for(int i=str.size()-1;i>=0;i--)
	{

		if(meaningfulchar&&str[i]==' ')
		{
			numofSpace++;
		}
		if(meaningfulchar==false&&str[i]!=' ')
		{
			endofchars = i;
			meaningfulchar = true;
		}
	}
	int currentPos=endofchars+2*numofSpace;
	for(int i=endofchars;i>=0;i--)
	{
		if(str[i]!=' ')
		{
			str[currentPos] = str[i];
			currentPos--;
		}
		else
		{
			str[currentPos]='0';
			str[currentPos-1]='2';
			str[currentPos-2]='%';
			currentPos-=3;
		}
	}
}