Cod sursa(job #1410540)

Utilizator mirceadinoMircea Popoveniuc mirceadino Data 31 martie 2015 09:28:25
Problema Ciclu hamiltonian de cost minim Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 1.51 kb
#include<algorithm>
#include<bitset>
#include<cmath>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<deque>
#include<fstream>
#include<iomanip>
#include<iostream>
#include<map>
#include<queue>
#include<set>
#include<stack>
#include<unordered_map>
#include<unordered_set>
#include<utility>
#include<vector>

using namespace std;

#ifdef HOME
const string inputFile = "input.txt";
const string outputFile = "output.txt";
#else
const string problemName = "hamilton";
const string inputFile = problemName + ".in";
const string outputFile = problemName + ".out";
#endif

const int INF = (1 << 29);

int N, M, sol;
int C[20][20];
int DP[(1 << 18) + 5][20];
vector<int> W[18];

int dp(int mask, int x) {
    if(DP[mask][x])
        return DP[mask][x];

    if((mask & (-mask)) == mask && x == 0)
        return 0;

    if((mask & (-mask)) == mask)
        return INF;

    DP[mask][x] = INF;

    for(auto y : W[x])
        if(mask & (1 << y))
            DP[mask][x] = min(DP[mask][x], dp(mask ^ (1 << x), y) + C[y][x]);

    return DP[mask][x];
}

int main() {
    int i, x, y, z, MASK;

#ifndef ONLINE_JUDGE
    freopen(inputFile.c_str(), "r", stdin);
    freopen(outputFile.c_str(), "w", stdout);
#endif

    scanf("%d%d", &N, &M);

    while(M--) {
        scanf("%d%d%d", &x, &y, &z);
        W[y].push_back(x);
        C[x][y] = z;
    }

    sol = INF;
    MASK = (1 << N) - 1;

    for(i = 0; i < N; i++)
        if(C[i][0])
            sol = min(sol, dp(MASK, i) + C[i][0]);

    printf("%d\n", sol);

    return 0;
}