Submission #1189360

#	Time	Username	Problem	Language	Result	Execution time	Memory
1189360		onbert	Designated Cities (JOI19_designated_cities)	C++20	16 / 100	191 ms	62420 KiB

designated_cities

#include <bits/stdc++.h>
using namespace std;
#define int long long
struct edge {
    int v, c, d;
    bool operator == (const edge &b) const {
        return (v == b.v && c == b.c && d == b.d);
    }
};

const int maxn = 2e5 + 5;
int n;
vector<edge> adj[maxn];
int ans[maxn];

pair<int,int> mxup[maxn];
int cur = 0;
void dfs0(int u, int f) {
    mxup[u] = {0, u};
    for (auto [v, c, d]:adj[u]) if (v != f) {
        dfs0(v, u);
        pair<int,int> val = mxup[v];
        val.first += c;
        mxup[u] = max(val, mxup[u]);
        cur += d;
    }
}
pair<int,int> firsttwo;
void dfs1(int u, int f, pair<int,int> mxdown) {
    ans[1] = max(cur, ans[1]);
    int curans2 = cur + max(mxdown, mxup[u]).first;
    // cout << u << " " << max(mxdown, mxup[u]).second << " " << cur << " " << max(mxdown, mxup[u]).first << " " << curans2 << endl;
    // cout << mxup[u].first << " " << mxup[u].second << endl;
    if (curans2 > ans[2]) {
        ans[2] = curans2;
        firsttwo = {u, max(mxdown, mxup[u]).second};
    }

    vector<pair<int,int>> vec;
    for (auto[ v, c, d]:adj[u]) if (v != f) {
        pair<int,int> val = mxup[v];
        val.first += c;
        vec.push_back(val);
    }
    sort(vec.rbegin(), vec.rend());

    for (auto [v, c, d]:adj[u]) if (v != f) {
        cur -= d, cur += c;
        pair<int,int> nxt = mxdown;
        if (adj[u].size() > 1) {
            if (vec[0].second != mxup[v].second) nxt = max(vec[0], nxt);
            else nxt = max(vec[1], nxt);
        }
        nxt.first += d;
        dfs1(v, u, nxt);
        cur += d, cur -= c;
    }
}

int RT;
int fa[maxn], cost[maxn];

int curans;
void dfs2(int u) {
    for (auto [v, c, d]:adj[u]) {
        curans += d;
        edge del = {u, d, c};
        adj[v].erase(find(adj[v].begin(), adj[v].end(), del));
        fa[v] = u;
        cost[v] = cost[u] + c;
        dfs2(v);
    }
}
void euler(int u, int val) {
    cost[u] += val;
    for (auto [v, c, d]:adj[u]) euler(v, val);
}

// int curans;
void update(int u) {
    curans += cost[u];
    return;
    vector<int> vec;
    while (cost[u]) {
        vec.push_back(u);
        u = fa[u];
    }
    reverse(vec.begin(), vec.end());
    for (int i:vec) {
        curans += cost[i];
        euler(i, -cost[i]);
    }
}

signed main() {
    ios::sync_with_stdio(0); cin.tie(0);
    cin >> n;
    int all = 0;
    for (int i=1;i<=n-1;i++) {
        int u, v, c, d;
        cin >> u >> v >> c >> d;
        adj[u].push_back({v, c, d});
        adj[v].push_back({u, d, c});
        all += c + d;
    }
    dfs0(1, 0);
    dfs1(1, 0, {0, -1});

    RT = firsttwo.first;
    cost[RT] = 0;
    curans = 0;
    dfs2(RT);
    // update(firsttwo.second);

    // curans = ans[2];
    
    for (int i=2;i<=2;i++) {
        pair<int,int> mx = {0, 0};
        for (int j=1;j<=n;j++) mx = max(make_pair(cost[j], j), mx);
        if (mx.first != 0) update(mx.second);
        ans[i] = curans;
    }

    int q;
    cin >> q;
    while (q--) {
        int x;
        cin >> x;
        cout << all - ans[x] << "\n";
    }
}

• Subtask 1: 0 / 6
• Subtask 2: 7 / 7
• Subtask 3: 9 / 9
• Subtask 4: 0 / 17
• Subtask 5: 0 / 17
• Subtask 6: 0 / 44