得分情况

刷题 华为机试

题目：一张100分试卷，判断10x2+单选10x4+多选5x8。从前往后做，错三个离场。给定一个分值，问有多少种情况

public class Main {
    private static int sum = 0;
    public static int[] scores = {2,2,2,2,2,2,2,2,2,2,4,4,4,4,4,4,4,4,4,4,8,8,8,8,8};
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        int target = in.nextInt();
        backtrack(0,0,0,target);
        System.out.println(sum);
    }
    private static void backtrack(int index, int score, int err, int target) {
        if (err>=3 || score>target) return;
        if (score == target) {
            sum++;
            return;
        }
        for (int i = index; i < scores.length; i++) {
            score += scores[i];
            backtrack(i+1, score, err, target);
            score -= scores[i];
            err++;
        }
    }
}