제출 #1123920

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1123920		kh0i	Cities (BOI16_cities)	C++20	59 / 100	6097 ms	172632 KiB

cities

#include "bits/stdc++.h"
using namespace std;

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...)
#endif

using ll = long long;
using pii = pair<int, int>;

#define F first
#define S second
#define sz(x) (int)((x).size())
#define all(x) (x).begin(), (x).end()

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll get_rand(ll l, ll r) {
    assert(l <= r);
    return uniform_int_distribution<ll> (l, r)(rng);
}

const int N = 1e5 + 3;
const int K = 5;

int n, k, m, c[K];
vector<pair<int, ll>> g[N];
ll f[N][1 << K];
bool vis[N][1 << K];

bool mini(ll &x, ll y){
    if(x <= y)
        return 0;
    x = y;
    return 1;
}

void solve(){
    cin >> n >> k >> m;
    for(int i = 0; i < k; ++i)
        cin >> c[i];
    for(int i = 1; i <= m; ++i){
        int u, v, w;
        cin >> u >> v >> w;
        g[u].emplace_back(v, w);
        g[v].emplace_back(u, w);
    }
    memset(f, 40, sizeof(f));
    priority_queue<pair<ll, pii>> pq;
    for(int i = 0; i < k; ++i)
        pq.push(make_pair(f[c[i]][1 << i] = 0, make_pair(c[i], 1 << i)));
    while(!pq.empty()){
        int u = pq.top().S.F;
        int mask = pq.top().S.S;
        pq.pop();
        if(vis[u][mask])
            continue;
        vis[u][mask] = 1;
        for(auto [v, w] : g[u]){
            int nmask = mask;
            for(int i = 0; i < k; ++i)
                if(c[i] == v)
                    nmask |= (1 << i);
            if(mini(f[v][nmask], f[u][mask] + w))
                pq.push(make_pair(-f[v][nmask], make_pair(v, mask)));

            int rev = ((1 << k) - 1) ^ mask, smask = rev;
            for(int smask = rev; smask; smask = (smask - 1) & rev){
                if(mini(f[v][mask | smask], f[u][mask] + f[v][smask] + w))
                    pq.push(make_pair(-f[v][mask | smask], make_pair(v, mask | smask)));
            }
        }
    }

    ll res = LLONG_MAX;
    for(int i = 1; i <= n; ++i){
        debug(i, f[i][(1 << k) - 1]);
        res = min(res, f[i][(1 << k) - 1]);
    }
    cout << res;
}

int32_t main() {
    cin.tie(nullptr)->sync_with_stdio(0);
    #define task "troll"
    if(fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    int test = 1;
//    cin >> test;
    for(int i = 1; i <= test; ++i){
//        cout << "Case #" << i << ": ";
        solve();
    }
    #ifdef LOCAL
        cerr << "\n[Time]: " << 1000.0 * clock() / CLOCKS_PER_SEC << " ms.\n";
    #endif
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

cities.cpp: In function 'int32_t main()':
cities.cpp:88:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   88 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
cities.cpp:89:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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