Next_Permutation()

[DeathLeap]

I have several questions about vectors and Next_Permutation().

I ALMOST wrote a program that prints out permutations from a user input.

A user inputs something, gets stored into a vector, if user inputs 0 = stop.

I push back the values into the vector. Sort it. Print it.

If the user inputs
> 1
> 2
> 3

I don't want to see permutations with number 1. So I did a little if statement.

My problem:

When I enter 1 2 3, it works fine. If I flip it, WITHOUT using the sort(), it doesn't work. No permutations.

Also, I feel like line 30 and 25 are not a good way to do what I want to do. Is there a better way to do it?

To better understand my problem, let me copy some outputs.

Enter Values:1
Enter Values:2
Enter Values:3
Enter Values:0


2 1 3
2 3 1
3 1 2
3 2 1

Ok, that worked fine. Now let's try 2.

Enter Values:2
Enter Values:1
Enter Values:3
Enter Values:0


3 1 2
3 2 1

Excuse me? Where is my permutations that start with 1?

Enter Values:3
Enter Values:2
Enter Values:1
Enter Values:0

Press any key to continue . . .

Now the program had enough of me..

  #include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main() {
	
	vector <int> squares;
	// x = user input
	int x;

	do
	{
		cout << "Enter Values:";
		cin >> x;
		if (x != 0)
		{
			squares.push_back(x);
		}
	} while (x!=0);
	
	/*//sort those values
	sort(squares.begin(), squares.end());*/

	int y = squares[0];

	//print the permutations
	do
	{
		if (y != squares[0])
		{
			for (int i = 0; i < squares.size(); i++)
			{
					cout << squares[i] << " ";
			}
		}
		cout << endl;
	} while (next_permutation(squares.begin(), squares.end()));

	system("PAUSE");
	return 0;
}

[JLBorges]

#include <iostream>
#include <vector>
#include <algorithm>

int main()
{
    std::vector <int> seq;

    int x ;
    do
    {
		std::cout << "Enter Value (enter 0 to end input): ";
		std::cin >> x;
		if( x != 0 ) seq.push_back(x) ;

    } while( x != 0 );

    std::sort( seq.begin(), seq.end() ) ; // sort the sequence

    if( !seq.empty() ) do
    {
        // std::size_t i = 1 ; ignore the element at front
        // seq.begin() + 1 ignore the element at front

        for( std::size_t i = 1; i < seq.size(); ++i ) std::cout << seq[i] << ' ' ;
        std::cout << '\n' ;

    } while( std::next_permutation( seq.begin() + 1, seq.end() ) );
}

[naraku9333]

From "\http://en.cppreference.com/w/cpp/algorithm/next_permutation

Transforms the range [first, last) into the next permutation from the set of all permutations that are lexicographically ordered with respect to operator< or comp.