3179-2020-java-2-3

import java.io.*;
import java.util.StringTokenizer;

class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer tokenizer = new StringTokenizer(reader.readLine());
        StringTokenizer tokenizer2 = new StringTokenizer(reader.readLine());

        int n = Integer.parseInt(tokenizer.nextToken());
        int m = Integer.parseInt(tokenizer.nextToken());

        int[] nums = new int[n];


        for(int i=0;i<n;i++)nums[i]=Integer.parseInt(tokenizer2.nextToken());

        int count=0;

        for(int i=0;i<n-1;i++)
            for(int j=i+1;j<n;j++)
                if(nums[i]+nums[j]==m)count++;

        System.out.print(count);
    }
}

做到现在都觉得这比赛题特别简单，也就课后习题的难度，属实是没有含金量是吧
也不知道今年难度会不会水涨船高