Submission #72617

#	Time	Username	Problem	Language	Result	Execution time	Memory
72617		karma	Cities (BOI16_cities)	C++11	51 / 100	6108 ms	232224 KiB

cities

#include<bits/stdc++.h>
#define For(i, a, b)  for(int i = a; i <= b; ++i)
#define Ford(i, a, b) for(int i = a; i >= b; --i)
#define FileName      "test"
#define ll            long long
#define ld            long double
#define ull           unsigned long long
#define pb            push_back
#define X             first
#define Y             second
//#define Karma

using namespace std;

template <typename T> inline void Cin(T &x)
{
    char c;
    T sign = 1;
    x = 0;
    for (c = getchar(); c < '0' || c > '9'; c = getchar())
        if (c == '-')
            sign = -1;
    for (; c >= '0' && c <= '9'; c = getchar())
        x = x * 10 + c - '0';
    x *= sign;
}

typedef pair<int, int> pii;
typedef pair<ll, int> plli;
const int N = 1e5 + 7;
const int M = (1 << 6);
const ll oo = 1e15 + 1;

int n, k, x, city[N], m, u, v, mask, mark;
set<pair<ll, pair<int, int>>> s;
ll f[N][M], c, w, cost;
vector<plli> a[N];
vector<int> b[M];

//f[u][mark] = f[v][mark] + c(u, v)
//f[u][mark] = f[u][mark'] + f[u][mark ^ mark']

int Bit(int i)
{
    return (1 << i);
}

void Enter()
{
    Cin(n); Cin(k); Cin(m);
    For(i, 0, Bit(k) - 1)
    {
        For(j, 0, Bit(k) - 1)
        {
            if((i & j) == 0)
                b[i].pb(j);
        }
    }
    fill_n(&f[0][0], N * M, oo);
    For(i, 1, k)
    {
        Cin(x);
        city[x] = i;
        f[x][Bit(i - 1)] = 0;
        s.insert({0, {x, Bit(i - 1)}});
    }
    For(i, 1, m)
    {
        Cin(u);
        Cin(v);
        Cin(c);
        a[u].pb({c, v});
        a[v].pb({c, u});
    }
}

void Solve()
{
    while(!s.empty())
    {
        w = s.begin()->X;
        plli p = s.begin()->Y;
        s.erase(s.begin());
        if(w > f[p.X][p.Y])
            continue;
        if(p.Y == Bit(k) - 1)
        {
            cout << w << '\n';
            return;
        }
        u = p.X;
        mask = p.Y;
        for(plli adj: a[u])
        {
            c = adj.X + f[u][mask];
            v = adj.Y;
            mark = mask;
            if(city[v])
                mark |= Bit(city[v] - 1);
            if(f[v][mark] > c)
            {
                f[v][mark] = c;
                s.insert({c, {v, mark}});
            }
            for(int bit: b[mask])
            {
                cost = c + f[v][bit];
                if(f[v][mark | bit] > cost)
                {
                    f[v][mark | bit] = cost;
                    s.insert({cost, {v, mark | bit}});
                }
            }
        }
    }
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
#ifdef Karma
    freopen(FileName".inp", "r", stdin);
    freopen(FileName".out", "w", stdout);
#endif // Karma

    Enter();
    Solve();

    return 0;
}

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 0 / 23
• Subtask 5: 0 / 26