Submission #1226416

#	Time	Username	Problem	Language	Result	Execution time	Memory
1226416		mariaclara	Closing Time (IOI23_closing)	C++20	100 / 100	498 ms	63728 KiB

closing

#include "closing.h"
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,int> pli;
typedef vector<int> vi;
typedef vector<ll> vl;
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define pb push_back
#define mk make_pair
#define fr first
#define sc second

vl calc_dist(int X, vector<vector<pii>> edges) {
    int N = sz(edges);
    vl dist(N, 1e12);
    vi vis(N);

    priority_queue<pli, vector<pli>, greater<pli>> pq;
    pq.push({0,X});
    dist[X] = 0;

    while(!pq.empty()) {
        auto [D,at] = pq.top();
        pq.pop();

        if(vis[at]) continue;
        vis[at] = 1;

        for(auto [viz, peso] : edges[at]) {
            if(dist[viz] > D + peso) {
                dist[viz] = D + peso;
                pq.push({D+peso, viz});
            }
        }
    }

    return dist;
}

int solve(ll K, vl a, vl b) {
    int n = sz(a);
    set<pli> op[3]; // -1, 1, 2

    if(K < 0) return - 2*n;

    for(int i = 0; i < n; i++) {
        op[1].insert({a[i], i});
        op[2].insert({b[i], i});
    }

    int l = 0;
    ll at_val = 0;
    vector<int> at(n);

    while(at_val <= K) {
        ll A = K+1, B = K+1;

        if(sz(op[0]) and sz(op[2]))
            A = (*op[0].begin()).fr + (*op[2].begin()).fr;

        if(sz(op[1])) 
            B = (*op[1].begin()).fr;

        if(A < B) {
            int i = (*op[0].begin()).sc;
            int j = (*op[2].begin()).sc;

            if(at[i] == 1) {
                op[0].erase({-a[i], i});
                op[1].erase({b[i]-a[i], i});
                at[i] = 0;
                op[1].insert({a[i], i});
                op[2].insert({b[i], i});
            }
            else {
                op[0].erase({-b[i]+a[i], i});
                at[i] = 1;
                op[0].insert({-a[i], i});
                op[1].insert({b[i]-a[i], i});
            }

            op[1].erase({a[j], j});
            op[2].erase({b[j], j});
            at[j] = 2;
            op[0].insert({-b[j]+a[j], j});

            at_val += A;
        }
        else {
            int i = (*op[1].begin()).sc;

            if(at[i] == 1) {
                op[0].erase({-a[i], i});
                op[1].erase({b[i]-a[i], i});
                at[i] = 2;
                op[0].insert({-b[i]+a[i], i});
            }
            else {
                op[1].erase({a[i], i});
                op[2].erase({b[i], i});
                at[i] = 1;
                op[0].insert({-a[i], i});
                op[1].insert({b[i]-a[i], i});
            }

            at_val += B;
        }

        if(at_val > K) break;
        l++;
    }

    return l;
}

int max_score(int N, int X, int Y, ll K, vi U, vi V, vi W) {
    vector<vector<pii>> edges(N);

    for(int i = 0; i+1 < N; i++)
        edges[U[i]].pb({V[i], W[i]}), edges[V[i]].pb({U[i], W[i]});

    vl distX = calc_dist(X, edges), distY = calc_dist(Y, edges);
    vl a(N), b(N);
    set<pli> cam;

    for(int i = 0; i < N; i++) {
        a[i] = min(distX[i], distY[i]);
        b[i] = max(distX[i], distY[i]);
        cam.insert({a[i], i});
    }

    int ans1 = 0, ans2 = 0;
    ll at_val = 0;

    while(!cam.empty()) {
        auto [D, ind] = *cam.begin();
        cam.erase(cam.begin());

        at_val += D;
        if(at_val > K) break;
        ans1++;
    }

    at_val = 0;

    for(int i = 0; i < N; i++) {
        if(distX[Y] == a[i] + b[i])
            at_val += a[i], a[i] = b[i]-a[i], b[i] = K+1, ans2++;
    }

    return max(ans1, ans2 + solve(K - at_val, a, b));
}

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