Submission #620780

#	Time	Username	Problem	Language	Result	Execution time	Memory
620780		wiwiho	Stations (IOI20_stations)	C++14	100 / 100	874 ms	796 KiB

stations

#include "stations.h"

#include <bits/stdc++.h>

#define iter(a) a.begin(), a.end()
#define lsort(a) sort(iter(a))
#define gsort(a) sort(iter(a), greater<>())
#define eb emplace_back
#define ef emplace_front
#define pob pop_back()
#define pof pop_front()
#define mp make_pair
#define F first
#define S second
#define uni(a) a.resize(unique(iter(a)) - a.begin())
#define printv(a, b) { \
    for(auto pv : a) b << pv << " "; \
    b << "\n"; \
}

using namespace std;

typedef long long ll;
typedef long double ld;

using pii = pair<int, int>;
using pll = pair<ll, ll>;

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

vector<int> label(int n, int k, vector<int> u, vector<int> v) {

    vector<vector<int>> g(n);
    vector<int> ans(n);
    int ts = -1;

    function<void(int, int, int)> dfs = [&](int now, int p, int d){
        if(d % 2 == 0) ans[now] = ++ts;
        for(int i : g[now]){
            if(i == p) continue;
            dfs(i, now, d + 1);
        }
        if(d % 2 == 1) ans[now] = ++ts;
    };

    for(int i = 0; i < n - 1; i++){
        g[u[i]].eb(v[i]);
        g[v[i]].eb(u[i]);
    }
    for(int i = 0; i < n; i++){
        if(g[i].size() > 1) continue;
        dfs(i, i, 0);
        break;
    }

    //cerr << "label ";
    //printv(ans, cerr);

    return ans;
}

int find_next_station(int s, int t, vector<int> c) {
    if(c.size() == 1) return c[0];

    int ty;
    if(s < c[0]) ty = 0;
    else ty = 1;
    //cerr << "find " << s << " -> " << t << "\n";
    //cerr << "ty " << ty << "\n";
    // 0:in 1:out

    if(ty == 0){
        // c.back(): parent
        int lst = s;
        for(int i = 0; i + 1 < (int)c.size(); i++){
            //cerr << "range " << c[i] << " : " << lst << " " << c[i] << "\n";
            if(lst < t && t <= c[i]) return c[i];
            lst = c[i];
        }
        return c.back();
    }
    else{
        // c[0]: parent
        int lst = s;
        for(int i = (int)c.size() - 1; i > 0; i--){
            //cerr << "range " << c[i] << " : " << lst << " " << c[i] << "\n";
            if(c[i] <= t && t < lst) return c[i];
            lst = c[i];
        }
        return c[0];
    }

}

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