Math Is Fun Forum

this is your code. I tried with it but after 6 hours it has crashed

#include <iostream>
#include <fstream>
#include <vector>
#include <math.h>
#include <windows.h>

using namespace std;

void testVals(vector<int> base, vector<bool> use, vector<int> test);
bool compare(int x, int y);

int main()
{
    int start = GetTickCount();
    for (int size = 2; size <= 32; size++)
    {
        cout << "Testing list size " << size << "..." << endl;
        vector<int> base;
        vector<bool> used;
        vector<int> test;
        for (int gen = 1; gen <= size; gen++)
        {
            base.push_back(gen);
            used.push_back(false);
        }
        testVals(base, used, test);
    }
    int end = GetTickCount();
    cout << "Time: " << (end - start) / 1000.0 << endl;
    return 0;
}

void testVals(vector<int> base, vector<bool> used, vector<int> test) {
    if (test.size() == base.size())
    {
        bool result = compare(test[test.size()-1], test[0]);
        if (result)
        {
            ofstream o("asdf.txt", ios::app);
            o << "Size: " << test.size() << endl;
            for (int x = 0; x < test.size(); x++)
            {
                o << test[x] << " ";
            }
            o << endl;
        }
        return;
    }

    for (int x = 0; x < used.size(); x++)
    {
        if (used[x] == false)
        {
            if (x != 0)
            {
                if (!compare(test[test.size()-1], base[x])) {
                    continue;
                }
            }
            used[x] = true;
            test.push_back(base[x]);
            testVals(base, used, test);
            test.erase(test.end()-1);
            used[x] = false;
        }
    }
}

bool compare(int x, int y)
{
    double temp = sqrt((double)x + y);
    const double amount = 0.00001;
    if (temp + amount > (int) temp && temp - amount < (int)temp)
    {
        return true;
    }
    return false;
}

If Ididn't wrong the values are:

x=3/7
y=-2/7
z=-1/7

Tell me if they are right please.

O my.. i let my program running all night long but it  crashed at size 43!!!!!! :\\\

this is the winner of the contest:
size=61

1,3,6,10,15,21,4,5,11,14,50,31,18,7,2,23,58,42,22,59,41,8,28,53,47,34, 30,51,49,32,17,19,45,36,13,12,37,27,54,46,35,29,52,48,33,16,20,44,56, 25,39,61,60,40,9,55,26,38,43,57,24

NICE WORK GUY!!

Can u find a list greater than 59?

my friend is winning the contest ..He's the only person who shown why 32 is the minimum number.
But there is another boy who found a 59 lenght sequence!!!!!

1,3,6,10,15,21,4,5,11,14,50,31,18,7,2,23,58,42,39,25,56,8,17,32,49,51, 13,36,28,53,47,34,30,19,45,55,26,38,43,57,24,12,37,44,20,29,52,48,33,16, 9,40,41,59,22,27,54,46,35

Krassi did u find an algorithm to create any circular sequences?

Yeah.. i dunno how did it! The one btw.. Instead one of my friend has shown why there isn't any circular number with
n<31 He was near the solution...I dunno how. As soon as my uni starts i ask to my friend to show me it

Sorry if I'm late, but u have been fantastic!!!! Thanks for ur work!

Thank u again Krassi and JohnFranklin

Or wait also tanh(x) is good. I think is perfect for your case

Try to plot it

tanh(x-3/5)+1

MARGIN+PICNUM*(MARGIN+WIDTH)+MARGIN+WIDTH=PICW/2

Let m MARGIN  p PICNUM  x WIDTH   q PICW
Then

m+p*(m+x)+m+x=q/2

px+x=q/2 -m -pm -m

x ( p+1 )=q/2-2m-pm

x= (q-4m-2pm)/2*(p+1)

x= (q-2m*(2+p)) / (2*( p+1 ))

WIDTH=( PICW-2MARGIN*(2+PICNUM))/(2*( PICNUM+1))

I have a friend called Hristo and he's hungarian. I think that he comes from Hungary. Is it right?

Tnx to Franklin too. But I think that all numbers have to be less than 50.
I try to ask but i think that the tips was n<50
So all the circular sequences with n<50 like krassi is doing . [only that 11+15 isn't a perfect square..so the sequence isn't correct ;| ]

U can decide is a  x1 is a minimum also by studying the graph of the function.
For example in a parabola with vertex in (-5,0)   -5 is a min! and max doesn't exist.