Submission #308579

#	Time	Username	Problem	Language	Result	Execution time	Memory
308579		lacito	Stations (IOI20_stations)	C++14	31.04 / 100	1020 ms	1024 KiB

stations

#include "stations.h"
#include <vector>

using namespace std;

const int M = 2000;

vector<vector<int>> g;
vector<int> intime, outtime;
int time;

void dfs(int v) {
    intime[v] = time++;
    for (int x : g[v])
        if (intime[x] == -1)
            dfs(x);
    outtime[v] = time++;
}

vector<int> label(int n, int k, vector<int> u, vector<int> v) {
	g.assign(n, {});
	intime.assign(n, -1);
	outtime.assign(n, -1);
	for (int i = 0; i < n - 1; i++) {
        g[u[i]].push_back(v[i]);
        g[v[i]].push_back(u[i]);
	}
	time = 0;
	dfs(0);
	vector<int> labels(n);
	for (int i = 0; i < n; i++) {
		labels[i] = M * intime[i] + outtime[i];
	}
	return labels;
}

inline int in(int label) {
    return label / M;
}

inline int out(int label) {
    return label % M;
}

inline bool inside(int label_a, int label_b) {
    return in(label_a) <= in(label_b) && out(label_b) <= out(label_a);
}

int find_next_station(int s, int t, vector<int> c) {
    int parent = -1;
    for (int x : c) {
        if (inside(x, s))
            parent = x;
    }
    for (int x : c) {
        if (inside(x, t) && x != parent)
            return x;
    }
	return parent;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 16
• Subtask 4: 10 / 10
• Subtask 5: 21.0422 / 61