题目描述

贪心

贪心

import java.util.*;

public class Main {

    static class Range {
        int l, r;

        public Range(int l, int r) {
            this.l = l;
            this.r = r;
        }
    }


    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        Range[] range = new Range[n];
        for (int i = 0; i < n; i++) {
            int l = scanner.nextInt();
            int r = scanner.nextInt();
            range[i] = new Range(l, r);
        }

        //使用lambda表达式进行比较并排序
        Arrays.sort(range, (a, b) -> a.r - b.r);

        int res = 0;
        int ed = Integer.MIN_VALUE;
        for (int i = 0; i < n; i++) {
            if (range[i].l > ed) {
                res++;
                ed = range[i].r;
            }
        }

        System.out.println(res);
    }
}