Cod sursa(job #1243535)

Utilizator diana97Diana Ghinea diana97 Data 16 octombrie 2014 00:17:25
Problema Ciclu hamiltonian de cost minim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.26 kb
#include <iostream>
#include <fstream>

using namespace std;

ifstream f ("hamilton.in");
ofstream g ("hamilton.out");

const int NMAX = 18 + 1 + 1;
const int INF = 0X3fffffff;

int n, m;
int cost[NMAX][NMAX];
int sol[NMAX][1 << NMAX];

void citeste() {
    int a, b, c;
    f >> n >> m;
    for (int i = 1; i <= m; i++) {
        f >> a >> b >> c;
        a++; b++;
        cost[a][b] = c;
    }
}

int hamilton (int nod, int configuratie) {
    if(sol[nod][configuratie] != 0) return sol[nod][configuratie];
    if (configuratie == (1 << (n + 1)) - 2) { //am ajuns la final (1111110)
        if (cost[nod][1] != 0) sol[nod][configuratie] = cost[nod][1];
        else sol[nod][configuratie] = INF; // nu e o solutie
    }
    else {
        int minim = INF, crt;
        for (int i = 2; i <= n; i++)
            if (cost[nod][i] != 0 && (configuratie & (1 << i)) == 0) { //fiecare vecin care nu este inca in configuratie
                crt = cost[nod][i] + hamilton(i, configuratie ^ (1 << i));
                minim = min(minim, crt);
            }
        sol[nod][configuratie] = minim;
    }
    return sol[nod][configuratie];
}

int main() {
    citeste();
    int c = hamilton(1, 1 << 1);
    if (c == INF) g << "Nu exista solutie";
    else g << c;
    g << '\n';
    return 0;
}