Submission #293846

#	Time	Username	Problem	Language	Result	Execution time	Memory
293846		Trickster	Highway Tolls (IOI18_highway)	C++14	0 / 100	35 ms	11384 KiB

highway

#include <algorithm>
#include <highway.h>
#include <string.h>
#include <iostream>
#include <stdio.h>
#include <vector>
#include <queue>
#include <cmath>
#include <set>
#include <map>

using namespace std;

#define maxN 200010
#define ff first
#define ss second
#define ll long long
#define pb push_back
#define mod 1000000007
#define pii pair <ll, ll>
// #pragma GCC target ("avx2")
// #pragma GCC optimization ("O3")
// #pragma GCC optimization ("unroll-loops")
ll bigmod(ll a,ll e) {if(e==0)return 1;ll x=bigmod(a*a%mod,e>>1);return e&1?x*a%mod:x;}

pii L[maxN];
int n, m, dis;
vector <pii> E[maxN];
vector <int> T[maxN];

int tap(vector <pii> v)
{
    int sz = v.size();
    int l = 0, r = sz-1, md, in = 0;
    while(l <= r) {
        md = (l+r)/2;

        vector <int> arr;
        for(int i = 0; i < m; i++) arr.pb(0);

        for(int i = 0; i < sz; i++)
            for(auto h: T[v[i].ss])
                arr[h] = (i <= md ? 1 : 0);

        int cur = ask(arr);

        if(dis != cur) r = md-1, in = md;
        else l = md+1;
    }
    return v[in].ss;
}

void find_pair(int N, vector <int> U, vector <int> V, int A, int B) 
{
    m = U.size(), n = N;

    for(int i = 0; i < m; i++) {
        E[U[i]].pb({V[i], i});
        E[V[i]].pb({U[i], i});
    }

    vector <int> arr;
    for(int i = 0; i < m; i++) arr.pb(0);

    dis = ask(arr);

    int l = 0, r = m-1, md, in = 0;
    while(l <= r) {
        md = (l+r)/2;

        vector <int> arr;
        for(int i = 0; i < m; i++) arr.pb((i <= md ? 1 : 0));

        int cur = ask(arr);

        if(dis != cur) r = md-1, in = md;
        else l = md+1;
    }

    queue <pii> Q;
    Q.push({U[in], 1});
    Q.push({V[in], 2});
    L[U[in]] = {0, 1};
    L[V[in]] = {0, 2};
    while(!Q.empty()) {
        int nd = Q.front().ff;
        int tp = Q.front().ss;
        Q.pop();

        for(auto i: E[nd]) {
            if(L[i.ff].ss) continue;

            L[i.ff] = {L[nd].ff+1, tp};
            Q.push({i.ff, tp});
            T[i.ff].pb(i.ss);
            T[nd].pb(i.ss);
        }
    }

    vector <pii> v;
    for(int i = 0; i < n; i++) if(L[i].ss == 1) v.pb({L[i].ff, i});

    sort(v.begin(), v.end());

    int s = tap(v);

    v.clear();
    for(int i = 0; i < n; i++) if(L[i].ss == 2) v.pb({L[i].ff, i});

    sort(v.begin(), v.end());

    int t = tap(v);

    answer(s, t);
}

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