Submission #433047

#	Time	Username	Problem	Language	Result	Execution time	Memory
433047		peuch	Stations (IOI20_stations)	C++17	100 / 100	899 ms	756 KiB

stations

#include "stations.h"
#include <bits/stdc++.h>
using namespace std;

int cnt;
vector<vector<int> > ar;
vector<int> ord;
vector<int> lbl;

void dfs(int cur, int pai, int prof){
	if(prof % 2 == 0) ord.push_back(cur);
	for(int i = 0; i < ar[cur].size(); i++){
		int viz = ar[cur][i];
		if(viz == pai) continue;
		dfs(viz, cur, prof + 1);
	}
	if(prof % 2 == 1) ord.push_back(cur);
}

vector<int> label(int n, int k, vector<int> u, vector<int> v) {
	ar = vector<vector<int> > (n);
	lbl = vector<int> (n);
	ord.clear();
	for(int i = 0; i < u.size(); i++){
		ar[u[i]].push_back(v[i]);
		ar[v[i]].push_back(u[i]);
	}
	dfs(0, 0, 0);
	assert(ord.size() == n);
	for(int i = 0; i < n; i++)
		lbl[ord[i]] = i;
	return lbl;
}

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

Compilation message (stderr)

stations.cpp: In function 'void dfs(int, int, int)':
stations.cpp:12:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |  for(int i = 0; i < ar[cur].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~
stations.cpp: In function 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)':
stations.cpp:24:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |  for(int i = 0; i < u.size(); i++){
      |                 ~~^~~~~~~~~~
In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from stations.cpp:2:
stations.cpp:29:20: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   29 |  assert(ord.size() == n);
      |         ~~~~~~~~~~~^~~~
stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:40:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |   for(int i = 0; i < c.size(); i++)
      |                  ~~^~~~~~~~~~

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