Submission #306508

#	Time	Username	Problem	Language	Result	Execution time	Memory
306508		smax	Stations (IOI20_stations)	C++17	100 / 100	1022 ms	1132 KiB

stations

#include "stations.h"
#include <vector>
using namespace std;

int ti;
vector<int> adj[1005];

void dfs(int u, int p, int d, vector<int> &labels) {
    if (d % 2 == 0)
        labels[u] = ti++;
    for (int v : adj[u])
        if (v != p)
            dfs(v, u, d + 1, labels);
    if (d % 2 == 1)
        labels[u] = ti++;
}

std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v) {
	std::vector<int> labels(n);

	ti = 0;
	for (int i=0; i<n; i++)
        adj[i].clear();
    for (int i=0; i<n-1; i++) {
        adj[u[i]].push_back(v[i]);
        adj[v[i]].push_back(u[i]);
    }
    dfs(0, -1, 0, labels);

	return labels;
}

int find_next_station(int s, int t, std::vector<int> c) {
    if (c.back() < s) {
        // odd depth
        if (t > s || t < c[0])
            return c[0];
        for (int i=0; i<(int)c.size()-1; i++)
            if (t >= c[i] && t < c[i+1])
                return c[i];
        return c.back();
    } else {
        // even depth
        if (t < s || t > c.back())
            return c.back();
        for (int i=(int)c.size()-1; i>0; i--)
            if (t <= c[i] && t > c[i-1])
                return 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