题目描述

blablabla

样例

blablabla

参考链接：https://blog.csdn.net/sinat_38816924/article/details/82934900

java 代码

import java.util.Arrays;
import java.util.Scanner;

public class Main {
    static class Interval implements Comparable<Interval>{
        int a;
        int b;

        public Interval(int a, int b) {
            this.a = a;
            this.b = b;
        }

        @Override
        public int compareTo(Interval y) {
            if(this.b!=y.b)
                return (this.b<y.b)?-1:1;
            if(this.a!=y.a)
                return (this.a<y.b)?-1:1;
            return 0;
        }
    }

    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        int n=scanner.nextInt();
        int count=1;
        Interval arr[]=new Interval[n];
        for (int i = 0; i < n; i++) {
            arr[i]=new Interval(scanner.nextInt(),scanner.nextInt());
        }
        Arrays.sort(arr);
        int newend=arr[0].b;
        for (int i = 1; i <n; i++) {
            if (newend<arr[i].a){
                count++;
                newend=arr[i].b;
            }
        }
        System.out.println(count);
    }
}