Cod sursa(job #2180919)

Utilizator andreisavulescuSavulescu Andrei andreisavulescu Data 21 martie 2018 12:10:38
Problema Problema Damelor Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb
#include <fstream>
#include <cmath>
using namespace std;
ifstream f("damesah.in");
ofstream g("damesah.out");
int n, x[14], nrsol = 0, ok = 0;
int col[14], dg1[26], dg2[26];

bool valid(int k)
{
    if((col[x[k]] == 0) && (dg1[k + x[k] - 1] == 0) && (dg2[n - k + x[k]] == 0)) //valid
        {
            col[x[k]] = dg1[k + x[k] - 1] = dg2[n - k + x[k]] = 1;
            return 1;
        }
    return 0;
}

void bt(int k)
{
    if(k <= n)
        for(int i = 1; i <= n; i++)
            {
                x[k] = i;
                if(valid(k) == 1)
                    {
                        bt(k + 1);
                        col[x[k]] = dg1[k + x[k] - 1] = dg2[n - k + x[k]] = 0;
                    }
            }
    else
        {
            if(ok == 0)
                {
                    for(int i = 1; i <= n; i++)
                        g << x[i] << ' ';
                    g << '\n';
                    ok = 1;
                }
            nrsol++;
        }
}
int main()
{
    f >> n;
    bt(1);
    g << nrsol;
    return 0;
}