Submission #307407

#	Time	Username	Problem	Language	Result	Execution time	Memory
307407		arthur_nascimento	Stations (IOI20_stations)	C++14	100 / 100	1081 ms	1284 KiB

stations

#include "stations.h"
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define debug
#define maxn 2020
int ini[maxn];
int fim[maxn];
int mrk[maxn];
int h[maxn];
vector<int> L[maxn];
 
int cur = 0;
void dfs(int x){
	debug("dfs %d\n",x);
	ini[x] = cur++;
	for(int i : L[x])
		if(ini[i] == 0 && i > 0){
			h[i] = 1 + h[x];
			dfs(i);
		}
	fim[x] = cur++;
}
 
std::vector<int> label(int n, int k, std::vector<int> u, std::vector<int> v) {
	cur = 0;
	for(int i=0;i<2*n;i++)
		L[i].clear(), h[i] = ini[i] = fim[i] = 0, mrk[i] = 0;
	for(int i=0;i<n-1;i++){
		L[u[i]].pb(v[i]);
		L[v[i]].pb(u[i]);
	}
	dfs(0);
	vector<int> ret;
	for(int i=0;i<n;i++){
		if(h[i]%2 == 0)
			ret.pb(ini[i]);
		else
			ret.pb(fim[i]);
	}

	for(int i : ret) mrk[i] = 1;
	for(int i=1;i<2*n;i++) mrk[i] += mrk[i-1];

	for(int &i : ret) i = mrk[i];
	
	for(int i : ret)
		debug("%d ",i);
	debug("\n");
	return ret;
}
 
int find_next_station(int s, int t, std::vector<int> c) {
	debug("qr %d %d ~",s,t); for(int i : c) debug("%d ",i); debug("\n");
	if(c.size() == 1) return c[0];
	sort(c.begin(), c.end());
	if(s < c[0]){
		// S é entrada, c[i] é saida
		int pai = c[c.size()-1];
		if(t < s) return pai;
		if(c.size() >= 2 && t > c[c.size()-2]) return pai;
		for(int i=0;i<c.size();i++){
			if(t <= c[i])
				return c[i];
		}
		
	}
	else {
		// S é saida, c[i] é entrada
		int pai = c[0];
		if(t > s) return pai;
		if(t < c[1]) return pai;
		for(int i=1;i<c.size()-1;i++){
			if(t < c[i+1]) return c[i];
		}
		return c[c.size()-1];
	}
}

Compilation message (stderr)

stations.cpp: In function 'void dfs(int)':
stations.cpp:15:8: warning: left operand of comma operator has no effect [-Wunused-value]
   15 |  debug("dfs %d\n",x);
      |        ^~~~~~~~~~
stations.cpp: In function 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)':
stations.cpp:48:9: warning: left operand of comma operator has no effect [-Wunused-value]
   48 |   debug("%d ",i);
      |         ^~~~~
stations.cpp:49:8: warning: statement has no effect [-Wunused-value]
   49 |  debug("\n");
      |       ~^~~~~
stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:54:8: warning: left operand of comma operator has no effect [-Wunused-value]
   54 |  debug("qr %d %d ~",s,t); for(int i : c) debug("%d ",i); debug("\n");
      |        ^~~~~~~~~~~~
stations.cpp:54:23: warning: right operand of comma operator has no effect [-Wunused-value]
   54 |  debug("qr %d %d ~",s,t); for(int i : c) debug("%d ",i); debug("\n");
      |                       ^
stations.cpp:54:48: warning: left operand of comma operator has no effect [-Wunused-value]
   54 |  debug("qr %d %d ~",s,t); for(int i : c) debug("%d ",i); debug("\n");
      |                                                ^~~~~
stations.cpp:54:64: warning: statement has no effect [-Wunused-value]
   54 |  debug("qr %d %d ~",s,t); for(int i : c) debug("%d ",i); debug("\n");
      |                                                               ~^~~~~
stations.cpp:62:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |   for(int i=0;i<c.size();i++){
      |               ~^~~~~~~~~
stations.cpp:73:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |   for(int i=1;i<c.size()-1;i++){
      |               ~^~~~~~~~~~~
stations.cpp:78:1: warning: control reaches end of non-void function [-Wreturn-type]
   78 | }
      | ^

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