Colorarea hartilor recursiv

//COLORAREA HARTILOR
#include <iostream>
#include <fstream>
#include <math.h>
using namespace std;

ifstream fin("adiacenta1.txt");

int A[50][50], st[50], n;

void Citire(int &n)
{
    int i, j;
    fin >> n;

    while (fin >> i >> j)
    {
        A[i][j] = A[j][i] = 1;
    }
    fin.close();
}


int Solutie(int k)
{
    return n == k;
}

void Tipar()
{
    for (int i = 1; i <= n; i++)
        cout << st[i] << " ";
    cout << "\n";
}


int Valid(int k)
{
    for (int i = 1; i < k; i++)
        if (st[i] == st[k] && A[i][k]==1 )
            return 0;

    return 1;
}


void bkt(int k)
{
    for (int i = 1; i <= 4; i++)
    {
        st[k] = i;
        if (Valid(k))
        {
            if (Solutie(k))
                Tipar();
            else
                bkt(k + 1);
        }
    }
}


int main()
{
    Citire(n);




    bkt(1);

    cout << "\n";
    system("pause");
    return 0;
}