Submission #1219036

#	Time	Username	Problem	Language	Result	Execution time	Memory
1219036		JooDdae	Highway Tolls (IOI18_highway)	C++20	12 / 100	51 ms	8604 KiB

highway

#include "highway.h"
#include<bits/stdc++.h>
using namespace std;
using ll = long long;

ll query(int M, vector<int> L) {
    vector<int> w(M, 0);
    for(auto x : L) w[x] = 1;
    return ask(w);
}

void find_pair(int N, vector<int> U, vector<int> V, int A, int B) {
    int M = U.size();
    vector<int> d(N, 0), p(N, 0);
    ll D = query(M, {});
    
    vector<vector<array<int, 2>>> v(N);
    for(int i=0;i<M;i++) {
        v[U[i]].push_back({V[i], i});
        v[V[i]].push_back({U[i], i});
    }

    queue<int> q;
    q.push(0), d[0] = 1;
    while(!q.empty()) {
        int u = q.front(); q.pop();
        for(auto [x, id] : v[u]) if(!d[x]) q.push(x), d[x] = d[u]+1, p[x] = id;
    }

    vector<int> L, P;
    for(int i=0;i<N;i++) if(d[i] == D/A+1) L.push_back(i), P.push_back(p[i]);

    int l = 1, r = (int)L.size()-1;
    while(l <= r) {
        int mid = (l+r) >> 1;
        if(query(M, vector<int>(P.begin(), P.begin()+mid)) == D) l = mid+1;
        else r = mid-1;
    }

    answer(0, L[r]);
}

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 0 / 6
• Subtask 4: 0 / 33
• Subtask 5: 0 / 18
• Subtask 6: 0 / 31