Submission #1099553

#	Time	Username	Problem	Language	Result	Execution time	Memory
1099553		Tymond	Stations (IOI20_stations)	C++17	100 / 100	628 ms	1040 KiB

stations

#include <bits/stdc++.h>
#include "stations.h"
using namespace std;
using ll = long long;
using ld = long double;
#define fi first
#define se second
#define vi vector<int>
#define vll vector<long long>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::high_resolution_clock::now().time_since_epoch().count());
inline int rand(int l,int r){return uniform_int_distribution<int>(l, r)(rng);}
inline ll rand(ll l,ll r){return uniform_int_distribution<ll>(l, r)(rng64);}
#ifdef DEBUG
auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";}
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X)
#else
#define debug(...){}
#endif
 
struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }
 
    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

vi col;
int timer = 0;
vector<vi> g;

void dfs(int v, int p, int f){
    if(f == 0){
        col[v] = timer++;
    }

    for(auto u : g[v]){
        if(u == p){
            continue;
        }
        dfs(u, v, 1 - f);
    }

    if(f){
        col[v] = timer++;
    }
}

vi label(int n, int k, vi u, vi v){
    k++;
    col.assign(n, 0);
    g.resize(n);
    for(int i = 0; i < n; i++){
        g[i].clear();
    }
    timer = 0;
    for(int i = 0; i < n - 1; i++){
        g[u[i]].pb(v[i]);
        g[v[i]].pb(u[i]);
    }

    dfs(0, 0, 0);
    return col;
}

int find_next_station(int s, int t, vi c){
    sort(all(c));
    if(sz(c) == 1){
        return c[0];
    }

    if(s == 0){
        for(auto ele : c){
            if(t <= ele){
                return ele;
            }
        }
        return c.back();
    }

    int cnt[2] = {0, 0};
    for(auto ele : c){
        if(ele < s){
            cnt[1]++;
        }else{
            cnt[0]++;
        }
    }

    if(cnt[0] > cnt[1]){
        //fs = 0
        for(int i = 0; i + 1 < sz(c); i++){
            if(t >= s && t <= c[i]){
                return c[i];
            }
        }
        return c.back();
    }else{
        //fs = 1
        for(int i = sz(c) - 1; i > 0; i--){
            if(t >= c[i] && t <= s){
                return c[i];
            }
        }
        return c[0];
    }
}
 
/*int main(){
    vi c = label(5, 10, {0, 1, 1, 2}, {1, 2, 3, 4});
    for(int i = 0; i < 5; i++){
        cout << c[i] << ' ';
    }
    cout << '\n';
    cout << find_next_station(c[2], c[0], {c[1], c[4]}) << '\n';
 
    return 0;
}*/

• Subtask 1: 5 / 5
• Subtask 2: 8 / 8
• Subtask 3: 16 / 16
• Subtask 4: 10 / 10
• Subtask 5: 61 / 61