题解 | #射击训练#

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

public class Main {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);

        while(in.hasNext()){
            solution(in);
        }
    }

    /**
     * 模拟法: 统计个数
     * @param in
     */
    private static void solution(Scanner in){
        int n = in.nextInt();

        int[] scores = new int[n];
        int[] count = new int[1001];

        for(int i=0; i<n; i++){
            scores[i] = in.nextInt();
            count[scores[i]]++;
        }

        Arrays.sort(scores);

        int multi;
        int result = 0;
        for(int i=0; i<n; i++){
            for(int j=i+1; j<n; j++){
                for(int k=j+1; k<n; k++){
                    multi = scores[i]*scores[j]*scores[k];
                    if(multi > 1000){
                        break;
                    }else{
                        count[scores[i]]--;
                        count[scores[j]]--;
                        count[scores[k]]--;
                        if(count[multi] > 0){
                            result++;
                        }
                        count[scores[i]]++;
                        count[scores[j]]++;
                        count[scores[k]]++;
                    }
                }
            }
        }

        System.out.println(result);
    }
}