题解 | #数组分组#

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {
    private static boolean[] isVisited;

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

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

    /**
     * 模拟法
     * @param in
     */
    private static void solution(Scanner in){
        int N = in.nextInt();

        int group3Sum = 0;
        int group5Sum = 0;
        int sum = 0;
        List<Integer> list = new ArrayList<>();
        for(int i=0; i<N; i++){
            int num = in.nextInt();
            if(num%5 == 0){
                group5Sum += num;
            }else if(num%3 == 0){
                group3Sum += num;
            }else{
                list.add(num);
            }
            sum += num;
        }

        // 总和奇数
        if(sum%2 != 0){
            System.out.println(false);
        }else{
            Integer[] array = list.toArray(new Integer[0]);
            isVisited = new boolean[array.length];

            boolean isEqual = operate(0, group3Sum, group5Sum, array);

            if(isEqual){
                System.out.println(true);
            }else{
                System.out.println(false);
            }
        }
    }

    /**
     * 递归
     * @param opTimes
     * @param group3Sum
     * @param group5Sum
     * @param array
     * @return
     */
    private static boolean operate(int opTimes, int group3Sum, int group5Sum, Integer[] array){
        if(opTimes == array.length){
            if(group3Sum == group5Sum){
                return true;
            }
            return false;
        }

        for(int i=0; i<array.length; i++){
            if(!isVisited[i]){
                isVisited[i] = true;

                if(operate(opTimes+1, group3Sum+array[i], group5Sum, array) || operate(opTimes+1, group3Sum, group5Sum+array[i], array)){
                    return true;
                }

                isVisited[i] = false;
            }
        }

        return false;
    }
}