Submission #985297

#	Time	Username	Problem	Language	Result	Execution time	Memory
985297		tvladm2009	봉쇄 시간 (IOI23_closing)	C++17	29 / 100	1085 ms	28200 KiB

closing

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
 
const int N = 2e5 + 7;
 
vector<pair<int, int>> g[N];
int ans = 0;
 
vector<ll> find_dist(int n, int x) {
    vector<ll> dist(n, -1);
    queue<int> q;
    q.push(x);
    dist[x] = 0;
    while (!q.empty()) {
        int u = q.front();
        q.pop();
        for (auto v : g[u]) {
            if (dist[v.first] == -1) {
                dist[v.first] = dist[u] + v.second;
                q.push(v.first);
            }
        }
    }
    return dist;
}
 
int max_score(int n, int X, int Y, ll K, vector<int> U, vector<int> V, vector<int> W) {
    for (int i = 0; i < n; ++i) {
        g[i].clear();
    }
    ans = 0;
    for (int i = 0; i < n - 1; ++i) {
        g[U[i]].push_back(make_pair(V[i], W[i]));
        g[V[i]].push_back(make_pair(U[i], W[i]));
    }
    vector<ll> distX = find_dist(n, X);
    vector<ll> distY = find_dist(n, Y);
    vector<ll> one(n, 0), two(n, 0);
    for (int i = 0; i < n; ++i) {
        one[i] = min(distX[i], distY[i]);
        two[i] = max(distX[i], distY[i]);
    }
    {
        vector<ll> aux = one;
        sort(aux.begin(), aux.end());
        ll sum = 0;
        for (int i = 0; i < n; ++i) {
            if (sum + aux[i] <= K) {
                ans++;
                sum += aux[i];
            }
        }
        if (distX[Y] + 1 > 2 * K) {
            return ans;
        }
    }
    vector<bool> counted(n, 0);
    ll d = distX[Y], between = 0;
    int cnt = 0;
    for (int i = 0; i < n; ++i) {
        if (distX[i] + distY[i] == d) {
            between += one[i];
            cnt++;
            counted[i] = 1;
        }
    }
    ll sum_other_two = 0;
    vector<int> ord2(n);
    iota(ord2.begin(), ord2.end(), 0);
    sort(ord2.begin(), ord2.end(), [&](int x, int y) {
        return two[x] < two[y];
    });
    int ptr = 0;
 
    vector<int> ord1(n);
    iota(ord1.begin(), ord1.end(), 0);
    sort(ord1.begin(), ord1.end(), [&](int x, int y) {
        return one[x] < one[y];
    });
    auto get_sum_other_one = [&](int twos, int ones) {
        if (ones == 0) {
            return 0LL;
        }
        ll sum = 0;
        for (int i = 0; i < n; ++i) {
            if (counted[ord1[i]] == 0) {
                sum += one[ord1[i]];
                ones--;
                if (ones == 0) {
                    break;
                }
            }
        }
        return sum;
    };
 
    for (int twos = 0; twos <= n; ++twos) {
        if (twos != 0) {
            sum_other_two += two[ord2[ptr]];
            counted[ord2[ptr]] = 1;
            if (distX[ord2[ptr]] + distY[ord2[ptr]] == d) {
                between -= one[ord2[ptr]];
                cnt--;
            }
            ptr++;
        }
 
        for (int ones = 0; ones + twos + cnt <= n; ++ones) {
            if (sum_other_two + between + get_sum_other_one(twos, ones) <= K) {
                ans = max(ans, 2 * twos + cnt + ones);
            }
        }
    }
    return ans;
}

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 9 / 9
• Subtask 3: 12 / 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