Submission #401666

#	Time	Username	Problem	Language	Result	Execution time	Memory
401666		dxz05	Stations (IOI20_stations)	C++14	100 / 100	1140 ms	816 KiB

stations

#include "stations.h"
#include <bits/stdc++.h>

using namespace std;

const int MAXN = 1011;

vector<int> g[MAXN];

int ID[MAXN], tin[MAXN], tout[MAXN], timer = 0;
void dfs(int v, int p, int dep){
    tin[v] = timer++;
    for (int u : g[v]){
        if (u != p) dfs(u, v, dep + 1);
    }
    tout[v] = timer++;
    ID[v] = (dep & 1 ? tin[v] : tout[v]);
}

bool line = true, binary = true;

vector<int> label(int n, int k, vector<int> U, vector<int> V) {
    for (int i = 0; i < n; i++) g[i].clear();
    timer = 0;

    for (int i = 0; i < n - 1; i++){
        g[U[i]].push_back(V[i]);
        g[V[i]].push_back(U[i]);
    }

    dfs(0, -1, 1);

	vector<int> labels(n, 0);
	for (int i = 0; i < n; i++){
        ID[i] /= 2;
        labels[i] = ID[i];
    }

	return labels;
}

int find_next_station(int s, int t, vector<int> c) {
    int sz = c.size();
    if (sz == 1) return c.back();

    if (c.front() > s){ // dep = odd
        int lf = s, rg = c[sz - 2];
        if (lf > t || rg < t) return c.back();

        int pos = lower_bound(c.begin(), c.end(), t) - c.begin();

        return c[pos];
    } else { // dep = even
        int lf = c[1], rg = s;
        if (lf > t || rg < t) return c.front();

        int pos = upper_bound(c.begin(), c.end(), t) - c.begin() - 1;

        return c[pos];
    }

    return c[0];
}

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