Submission #999150

#	Time	Username	Problem	Language	Result	Execution time	Memory
999150		mdn2002	Closing Time (IOI23_closing)	C++17	17 / 100	321 ms	76896 KiB

closing

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

long long dp[3003][6003][2][2];
int max_score(int n, int x, int y, long long k, vector<int> U, vector<int> V, vector<int> W) {
    x ++, y ++;
    vector dis(n + 1, vector<long long>(2));
    vector<vector<pair<int, long long>>> gr(n + 1);

    for (int i = 0; i < n - 1; i ++) {
        int u = U[i] + 1, v = V[i] + 1, w = W[i];
        gr[u].push_back({v, w});
        gr[v].push_back({u, w});
    }

    function<void(int, int, int)> dfs = [&] (int v, int p, int wt) {
        for (auto [u, w] : gr[v]) {
            if (u == p) continue;
            dis[u][wt] = dis[v][wt] + w;
            dfs(u, v, wt);
        }
    };
    dfs(x, 0, 0), dfs(y, 0, 1);

    vector<int> vc, path, onpath(n + 1);
    function<void(int, int)> go = [&] (int v, int p) {
        vc.push_back(v);
        if (v == y) path = vc;
        for (auto [u, w] : gr[v]) {
            if (u == p) continue;
            go(u, v);
        }
        vc.pop_back();
    };
    go(x, 0);

    long long minstart = 0, mn = 1e15;
    for (int i = 1; i <= n; i ++) {
        if (max(dis[i][0], dis[i][1]) < mn) {
            minstart = i;
            mn = max(dis[i][0], dis[i][1]);
        }
    }

    for (auto x : path) {
        onpath[x] += 1;
        if (x == minstart) break;
    }
    for (int i = path.size() - 1; i >= 0; i --) {
        int x = path[i];
        onpath[x] += 2;
        if (x == minstart) break;
    }

    int ans = 0;
    function f = [&] {
        vector<int> did(n + 1);
        multiset<pair<long long, int>> s;
        for (int i = 1; i <= n; i ++) {
            s.insert({dis[i][0], i});
            s.insert({dis[i][1], i});
        }
        int cnt = 0;
        vector<int> v;

        while (s.size()) {
            auto [x, y] = *s.begin();
            s.erase(s.begin());
            if (did[y]) continue;
            if (x > k) break;
            k -= x;
            did[y] = 1;
            cnt ++;
        }
        if (k >= 0) return cnt;
        return -100000000;
    };

    long long kk = k;
    ans = f();
    if (dis[y][0] > 2 * k) return ans;
    k = kk;
    for (int i = 1; i <= n; i ++) {
        for (int j = 0; j <= 2 * n; j ++) {
            dp[i][j][0][0] = dp[i][j][0][1] = dp[i][j][1][0] = dp[i][j][1][1] = 1e16;
        }
    }
    vector dpp(2 * (n + 1), vector (2, vector<long long>(2, 1e16)));

    vector<int> siz(n + 1);
    function<void(int, int)> calcsiz = [&] (int x, int p) {
        siz[x] = 1;
        for (auto [u, w] : gr[x]) {
            if (u == p) continue;
            calcsiz(u, x);
            siz[x] += siz[u];
        }
    };
    calcsiz(minstart, 0);

    map<vector<int>, int> did;
    function<void(int, int, int, int)> calc = [&] (int x, int p, int rx, int ry) {
        if (did[{x, rx, ry}]) return;
        did[{x, rx, ry}] = 1;
        if (rx == 0 && ry == 0) dp[x][0][rx][ry] = 0;
        if (rx && ry == 0) dp[x][1][rx][ry] = min(dp[x][1][rx][ry], dis[x][0]);
        if (ry && rx == 0) dp[x][1][rx][ry] = min(dp[x][1][rx][ry], dis[x][1]);
        if (rx && ry) dp[x][2][rx][ry] = min(dp[x][2][rx][ry], max(dis[x][0], dis[x][1]));

        int sumsiz = 1;
        for (auto [u, w] : gr[x]) {
            if (u == p) continue;
            calc(u, x, rx, ry);
            if (rx && ry) {
                if (onpath[u] == 0) calc(u, x, 0, 0);
                if (onpath[u] != 1) calc(u, x, 0, 1);
                if (onpath[u] != 2) calc(u, x, 1, 0);
            }
            else if (rx && onpath[u] != 1) calc(u, x, 0, ry);
            else if (ry && onpath[u] != 2) calc(u, x, rx, 0);

            for (int i = 0; i <= rx; i ++) {
                for (int j = 0; j <= ry; j ++) {
                    for (int z = 2 * siz[u]; z >= 0; z --) {
                        for (int k = 2 * sumsiz; k >= 0; k --) {
                            dpp[k + z][rx][ry] = min(dpp[k + z][rx][ry], dp[x][k][rx][ry] + dp[u][z][i][j]);
                        }
                    }
                }
            }
            sumsiz += siz[u];
            for (int z = 0; z <= 2 * sumsiz; z ++) {
                dp[x][z][rx][ry] = dpp[z][rx][ry];
                dpp[z][rx][ry] = 1e16;
            }
        }
    };
    calc(minstart, 0, 1, 1);

    for (int i = 0; i <= 2 * n; i ++) {
        if (k >= dp[minstart][i][1][1]) ans = max(ans, i);
    }
    return ans;
}

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 9 / 9
• Subtask 3: 0 / 12
• Subtask 4: 0 / 14
• Subtask 5: 0 / 9
• Subtask 6: 0 / 11
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 17