````
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.sql.Time;
import java.util.Comparator;
import java.util.Iterator;
import java.util.TreeSet;
public class Main
{
public static void main(String[] args) throws NumberFormatException, IOException
{
int last=-1;
int sum=0;
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
int N=Integer.parseInt(bufferedReader.readLine());
TreeSet<p> treeSet=new TreeSet<>(new comparaab());
for (int i = 0; i < N; i++)
{
String[] strings=bufferedReader.readLine().split(" ");
treeSet.add(new p(Integer.parseInt(strings[0]),Integer.parseInt(strings[1])));
}
for (Iterator iterator = treeSet.iterator(); iterator.hasNext();)
{
p p = (p) iterator.next();
if(p.begintime<last)
{
continue;
}
last=p.endtime;
sum++;
}
System.out.println(sum);
}
}
class p
{
int begintime;
int endtime;
public p(int order, int time)
{
super();
this.begintime = order;
this.endtime = time;
}
}
class comparaab implements Comparator<p>
{
@[Override](/user/542747)
public int compare(p o1, p o2)
{
if(o1.endtime==o2.endtime)
{
return o1.begintime-o2.begintime;
}
return o1.endtime-o2.endtime;
}
}
````
求关
by 0_QAQ_0 @ 2023-12-15 08:54:56
@[fhzmmax](/user/969032) 关注喽
by swan999 @ 2023-12-15 16:52:58