Submission #1194007

#	Time	Username	Problem	Language	Result	Execution time	Memory
1194007		_callmelucian	Toll (APIO13_toll)	C++17	16 / 100	1 ms	2628 KiB

toll

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

using ll = long long;
using ld = long double;
using pl = pair<ll,ll>;
using pii = pair<int,int>;
using tpl = tuple<int,int,int>;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

struct DSU {
    vector<int> lab, weight;
    DSU (int sz) : lab(sz + 1, -1), weight(sz + 1) {}

    int get (int u) {
        if (lab[u] < 0) return u;
        return lab[u] = get(lab[u]);
    }

    void asgn (int u, int cur) { weight[get(u)] = cur; }

    bool unite (int a, int b) {
        a = get(a), b = get(b);
        if (a == b) return 0;
        if (-lab[a] < -lab[b]) swap(a, b);
        weight[a] += weight[b];
        lab[a] += lab[b], lab[b] = a;
        return 1;
    }
};

const int mn = 1e5 + 5;
ll minWeight[30][30], component[mn], cmpr[mn];
ll subtr[mn], sumWeight[mn], curCost, cnt;
vector<pii> adj[mn];
bool vis[30];

void dfs (int u, int p) {
    subtr[u] = sumWeight[u], cnt++, vis[u] = 1;
    for (auto [v, w] : adj[u]) {
        if (v == p) continue;
        if (!vis[v]) {
            dfs(v, u);
            subtr[u] += subtr[v];
            curCost += w * subtr[v];
        }
    }
}

int main()
{
//    freopen("TOLL.inp", "r", stdin);
//    freopen("TOLL.out", "w", stdout);

    ios::sync_with_stdio(0);
    cin.tie(0);

    /// read input & prepare DSU
    int n, m, k; cin >> n >> m >> k;
    vector<tpl> edge(m);
    vector<pii> newEdge(k);

    for (auto &cur : edge) {
        int a, b, c; cin >> a >> b >> c;
        cur = make_tuple(c, a, b);
    }
    sort(all(edge));

    DSU initdsu(n), dsu(n);
    for (auto &cur : newEdge) {
        int a, b; cin >> a >> b;
        cur = make_pair(a, b);
        initdsu.unite(a, b);
    }

    vector<int> weight(n + 1);
    for (int i = 1; i <= n; i++) {
        cin >> weight[i];
        dsu.asgn(i, weight[i]);
    }

    /// classify edge
    vector<tpl> unused;
    for (int i = 0; i < m; i++) {
        int a, b, c; tie(c, a, b) = edge[i];
        if (initdsu.unite(a, b)) dsu.unite(a, b);
        else unused.emplace_back(a, b, c);
    }

    /// re-index connected components
    int counter = 0;
    for (int i = 1; i <= n; i++)
        if (i == dsu.get(i))
            cmpr[i] = ++counter, sumWeight[counter] = dsu.weight[i];
    for (int i = 1; i <= n; i++)
        component[i] = cmpr[dsu.get(i)];

    /// process unused edges
    for (int i = 1; i <= counter; i++)
        for (int j = 1; j <= counter; j++) minWeight[i][j] = LLONG_MAX;
    for (auto [a, b, c] : unused) {
        int u = component[a], v = component[b];
        minWeight[u][v] = minWeight[v][u] = min(minWeight[u][v], ll(c));
    }

    /// try subsets of new edges
    ll ans = 0;
    for (int mask = 0; mask < (1 << k); mask++) {
        for (int i = 0; i < k; i++) {
            if (mask & (1 << i)) continue;
            int a, b; tie(a, b) = newEdge[i];
            a = component[a], b = component[b];
            adj[a].emplace_back(b, minWeight[a][b]);
            adj[b].emplace_back(a, minWeight[a][b]);
        }
        curCost = cnt = 0, dfs(component[1], -1);
        fill(vis + 1, vis + 1 + counter, 0);
        for (int i = 1; i <= counter; i++) adj[i].clear();

        if (cnt == counter) {
            ans = max(ans, curCost);
        }
    }
    cout << ans;

    return 0;
}

• Subtask 1: 16 / 16
• Subtask 2: 0 / 18
• Subtask 3: 0 / 22
• Subtask 4: 0 / 22
• Subtask 5: 0 / 22