variable is not permanently added

[TheDomesticUser2]

Hello. I am trying to create a piece of code that takes an input from the user, and sends it similar to a pyramid. For example,

Input: Bear
B
Be
Bea
Bear
Bea
Be
B

But when spaces are added, this happens
Input: Teddy Bear
T
Te
Ted
Tedd
Teddy
Teddy // As you can see, it doesn't switch over to the next letter
Teddy B


I am sorry if this may sound confusing. There is a comment in my code explaining this.

#include <iostream>
#include <string>
#include <fstream>

using namespace std;

int main()
{

	string fileName = "testing.txt";
	ofstream outputFile;

	outputFile.open(fileName);

	if (outputFile.is_open())
	{
		string characters;
		cout << "Enter the string of words" << endl;
		getline(cin, characters);

		for (int i = 0; i < characters.length(); i++)
		{
			for (int j = 0; j < i; j++)
			{
				if (characters[j] != ' ')
					outputFile << characters[j];

				else if (characters[j + 1] == ' ') // j is not permanently added by 1
					outputFile << characters[j];
			}

			if (i != 0)
				outputFile << endl;

		}

		for (int j = characters.length(); j >= 0; j--)
		{
			for (int x = 0; x < j; x++)
			{
				if (characters[x] != ' ')
					outputFile << characters[x];
			}

			outputFile << endl;
		}

		outputFile.close();
	}

	else
		cout << "File " << fileName << " not opened" << endl;


	cin.get();
	return 0;
}

[mbozzi]

#include <iostream>
#include <string>
#include <cctype>

int main()
{
    std::string line;
    std::getline(std::cin, line);
    
    for (std::string::size_type i = 0; i < line.size(); ++i)
    {
        if (std::isspace(line[i])) 
            continue;
        
        std::cout << line.substr(0, i + 1) << '\n';
    }
}

Live demo:
http://coliru.stacked-crooked.com/a/d6a4ec98fa7cf949