Submission #417388

#	Time	Username	Problem	Language	Result	Execution time	Memory
417388		wiwiho	Highway Tolls (IOI18_highway)	C++14	5 / 100	3091 ms	21860 KiB

highway

#include "highway.h"

#include <bits/stdc++.h>
#include <bits/extc++.h>

#define StarBurstStream ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define iter(a) a.begin(), a.end()
#define riter(a) a.rbegin(), a.rend()
#define lsort(a) sort(iter(a))
#define gsort(a) sort(riter(a))
#define pb(a) push_back(a)
#define eb(a) emplace_back(a)
#define pf(a) push_front(a)
#define ef(a) emplace_front(a)
#define pob pop_back()
#define pof pop_front()
#define mp(a, b) make_pair(a, b)
#define F first
#define S second
#define mt make_tuple
#define gt(t, i) get<i>(t)
#define tomax(a, b) ((a) = max((a), (b)))
#define tomin(a, b) ((a) = min((a), (b)))
#define topos(a) ((a) = (((a) % MOD + MOD) % MOD))
#define uni(a) a.resize(unique(iter(a)) - a.begin())
#define printv(a, b) {bool pvaspace=false; \
for(auto pva : a){ \
    if(pvaspace) b << " "; pvaspace=true;\
    b << pva;\
}\
b << "\n";}

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<ld, ld>;
using tiii = tuple<int, int, int>;

const ll MOD = 1000000007;
const ll MAX = 2147483647;

template<typename A, typename B>
ostream& operator<<(ostream& o, pair<A, B> p){
    return o << '(' << p.F << ',' << p.S << ')';
}

ll ifloor(ll a, ll b){
    if(b < 0) a *= -1, b *= -1;
    if(a < 0) return (a - b + 1) / b;
    else return a / b;
}

ll iceil(ll a, ll b){
    if(b < 0) a *= -1, b *= -1;
    if(a > 0) return (a + b - 1) / b;
    else return a / b;
}

int n, m;

ll query(vector<int> qry){
    ll tmp = ask(qry);
//    cerr << "query " << tmp << "  ";
//    printv(qry, cerr);
    return tmp;
}

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

    vector<vector<pii>> g(n);
    for(int i = 0; i < m; i++){
        int u = U[i], v = V[i];
        g[u].eb(mp(v, i));
        g[v].eb(mp(u, i));
    }

    vector<int> qry(m);
    ll dis = query(qry);

    int l = 0, r = m - 1;
    while(l < r){
        int mid = (l + r) / 2;
        fill(qry.begin() + l, qry.begin() + mid + 1, 1);
//        cerr << l << " " << r << " " << mid << "\n";
        if(query(qry) != dis){
            r = mid;
            fill(qry.begin() + l, qry.begin() + mid + 1, 0);
        }
        else l = mid + 1;
    }

    int e = l;
    int u = U[e], v = V[e];
//    cerr << e << " " << u << " " << v << "\n";

    auto getdis = [g](int s){
        vector<int> d(n, -1);
        vector<int> p(n, -1);
        queue<int> q;
        q.push(s);
        d[s] = 0;
        while(!q.empty()){
            int now = q.front();
            q.pop();
            for(pii i : g[now]){
                if(d[i.F] != -1) continue;
                p[i.F] = i.S;
                d[i.F] = d[now] + 1;
                q.push(i.F);
            }
        }
        return mp(d, p);
    };

    vector<int> du, pu, dv, pv;
    tie(du, pu) = getdis(u);
    tie(dv, pv) = getdis(v);
    vector<int> us, vs;
    for(int i = 0; i < n; i++){
        if(du[i] < dv[i]) us.eb(i);
        else vs.eb(i);
    }
    fill(iter(qry), 1);
    for(int i : us) qry[pu[i]] = 0;
    for(int i : vs) qry[pv[i]] = 0;
    qry[e] = 0;
//    cerr << "u " << " ";
//    printv(us, cerr);
//    cerr << "v " << " ";
//    printv(vs, cerr);

    sort(iter(us), [du](int a, int b){ return du[a] < du[b]; });
    sort(iter(vs), [dv](int a, int b){ return dv[a] < dv[b]; });

    auto owo = [qry, dis](vector<int>& s, vector<int>& p){
        int l = 0, r = (int)s.size() - 1;
        while(l < r){
            int mid = (l + r + 1) / 2;
            vector<int> tmp = qry;
            for(int i = mid; i <= r; i++) tmp[p[s[i]]] = 1;
//            cerr << "test " << l << " " << r << " " << mid << "\n";
            if(query(tmp) == dis) r = mid - 1;
            else l = mid;
        }
        return s[l];
    };

    int v1 = owo(us, pu);
    int v2 = owo(vs, pv);

//    cerr << v1 << " " << v2 << "\n";
    answer(v1, v2);
}

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