Submission #828280

#	Time	Username	Problem	Language	Result	Execution time	Memory
828280		tomruk	Stations (IOI20_stations)	C++17	100 / 100	633 ms	824 KiB

stations

#include "stations.h"
#include <bits/stdc++.h>
#define N 1005
using namespace std;
int tin[N],tout[N];
int d[N];
vector<int> adj[N];
int timer = 0;
void dfs(int v,int par){
	tin[v] = timer++;
	for(auto u:adj[v]){
		if(u == par)
			continue;
		d[u] = d[v] + 1;
		dfs(u,v);
	}
	tout[v] = timer++;
}
vector<int> label(int n, int k, vector<int> u, vector<int> v) {
	for(int i = 0;i<n;i++){
		adj[i].clear();
	}
	timer = 0;
	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);
	vector<int> ret(n,0);
	vector<int> compress;
	for(int i = 0;i<n;i++){
		if(d[i] & 1)
			ret[i] = tin[i];
		else ret[i] = tout[i];
		compress.push_back(ret[i]);
	}
	sort(compress.begin(),compress.end());
	for(int i = 0;i<n;i++){
		ret[i] = lower_bound(compress.begin(),compress.end(),ret[i]) - compress.begin();
	}
	return ret;
}

int find_next_station(int s, int t, vector<int> c){
	if(c.size() == 1)
		return c[0];
	if(c[0] > s){
		int l = s;
		int r = c[c.size()-2];
		if(t < l || t > r)
			return c.back();
		int x = 1e9;
		for(int i = 0;i<c.size()-1;i++){
			if(c[i] >= t)
				x = min(x,c[i]);
		}
		return x;
	}
	else{
		int l = c[1];
		int r = s;
		if(t < l || t > r)
			return c[0];
		int x = 0;
		for(int i = 1;i<c.size();i++){
			if(c[i] <= t)
				x = max(x,c[i]);
		}
		return x;
	}
}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:53:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |   for(int i = 0;i<c.size()-1;i++){
      |                 ~^~~~~~~~~~~
stations.cpp:65:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |   for(int i = 1;i<c.size();i++){
      |                 ~^~~~~~~~~

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