Submission #944912

#	Time	Username	Problem	Language	Result	Execution time	Memory
944912		PenguinsAreCute	Stations (IOI20_stations)	C++17	76 / 100	611 ms	1652 KiB

stations

#include "stations.h"
#include <bits/stdc++.h>
using namespace std;
#define MAXN 1005
vector<int> a[MAXN];
int pre[MAXN], post[MAXN], h[MAXN];
int c;
void dfs(int x, int p) {
	if(h[x]&1) pre[x] = c++;
	for(auto i: a[x]) if(i != p) {h[i] = h[x] + 1; dfs(i, x);}
	if(!(h[x]&1)) pre[x] = (c++);
}
std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v) {
	c = 0; h[0] = 0;
	for(int i = 0; i < MAXN; i++) a[i].clear();
	std::vector<int> labels(n);
	for(int i = 0; i < n - 1; i++) {
		a[u[i]].push_back(v[i]);
		a[v[i]].push_back(u[i]);
	}
	dfs(0, -1);
	for (int i = 0; i < n; i++) labels[i]=pre[i]<<1|(h[i]&1);
	return labels;
}
int find_next_station(int s, int t, std::vector<int> c) {
	if(s & 1) {
		if(t < s) return end(c)[-1];
		auto it = lower_bound(c.begin(),c.end(),t&(-2));
		if(it == c.end()) return end(c)[-1];
		return (*it);
	} else {
		if(t > s) return c[0];
		auto it = upper_bound(c.begin(),c.end(),t|1);
		if(it == c.begin()) return c[0];
		return (*(--it));
	}
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 16 / 16
• Subtask 4: 10 / 10
• Subtask 5: 50 / 61