Submission #1267808

#	Time	Username	Problem	Language	Result	Execution time	Memory
1267808		CodeLakVN	Cities (BOI16_cities)	C++20	100 / 100	1699 ms	38128 KiB

cities

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

#define task "main"
#define F first
#define S second
#define ii pair<int, int>
#define il pair<int, long long>
#define li pair<long long, int>
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)

template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }

template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }

template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }

const int MAX_N = (int)1e5 + 5;
const long long INF = (long long)1e18 + 1408;

int nNode, nEdge, k;
int special[6];
vector<ii> adj[MAX_N];

long long dp[MAX_N][1 << 5];

void solve() {
    cin >> nNode >> k >> nEdge;
    FOR(i, 0, k - 1) cin >> special[i];
    FOR(i, 1, nEdge) {
        int u, v, w;
        cin >> u >> v >> w;
        adj[u].push_back({v, w});
        adj[v].push_back({u, w});
    }

    memset(dp, 0x3f, sizeof(dp));
    FOR(i, 0, k - 1) dp[special[i]][1 << i] = 0;
    priority_queue<li, vector<li>, greater<li>> pq;
    FOR(mask, 1, (1 << k) - 1) {
        FOR(u, 1, nNode)
            for (int submask = (mask - 1) & mask; submask; submask = (submask - 1) & mask)
                minimize(dp[u][mask], dp[u][submask] + dp[u][mask ^ submask]);

        FOR(u, 1, nNode) if (dp[u][mask] < INF)
            pq.push({dp[u][mask], u});
        while (!pq.empty()) {
            li tmp = pq.top();
            pq.pop();
            int u = tmp.S;
            if (dp[u][mask] < tmp.F) continue;
            for (ii e : adj[u]) {
                int v = e.F, w = e.S;
                if (minimize(dp[v][mask], dp[u][mask] + w))
                    pq.push({dp[v][mask], v});
            }
        }
    }

    cout << dp[special[0]][(1 << k) - 1];
}

int32_t main() {
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    bool multitest = 0;
    int numTest = 1;
    if (multitest) cin >> numTest;

    while (numTest--) {
        solve();
    }

    return 0;
}

/* Lak lu theo dieu nhac!!!! */

Compilation message (stderr)

cities.cpp: In function 'int32_t main()':
cities.cpp:78:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
cities.cpp:79:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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