每日一练69——Java减去总和(8kyu)

题目

注意！这个kata比普通的8-kyu katas更难

完成，其获得的输入号码的功能n，使得n >= 10和n < 10000，则：

求和的所有数字相加n。
从中减去总和n，这是你的新数据n。
如果新n的位于下面的列表中，则返回关联的水果，否则返回任务1。
例
n = 325
sum = 3 + 2 + 5 = 10
n = 325-10 = 315（不在列表中）
sum = 3 + 1 + 5 = 9
n = 315-9 = 306（不在列表中）
sum = 3 + 0 + 6 = 9
n = 306-9 = 297（不在列表中）
。
。
。
...直到找到下面列表中的前n个。

没有预加载的代码可以帮助您。 这与编码技巧无关; 在你编码之前思考思考。

1-kiwi
2-pear
3-kiwi
4-banana
5-melon
6-banana
7-melon
8-pineapple
9-apple
10-pineapple
11-cucumber
12-pineapple
13-cucumber
14-orange
15-grape
16-orange
17-grape
18-apple
19-grape
20-cherry
21-pear
22-cherry
23-pear
24-kiwi
25-banana
26-kiwi
27-apple
28-melon
29-banana
30-melon
31-pineapple
32-melon
33-pineapple
34-cucumber
35-orange
36-apple
37-orange
38-grape
39-orange
40-grape
41-cherry
42-pear
43-cherry
44-pear
45-apple
46-pear
47-kiwi
48-banana
49-kiwi
50-banana
51-melon
52-pineapple
53-melon
54-apple
55-cucumber
56-pineapple
57-cucumber
58-orange
59-cucumber
60-orange
61-grape
62-cherry
63-apple
64-cherry
65-pear
66-cherry
67-pear
68-kiwi
69-pear
70-kiwi
71-banana
72-apple
73-banana
74-melon
75-pineapple
76-melon
77-pineapple
78-cucumber
79-pineapple
80-cucumber
81-apple
82-grape
83-orange
84-grape
85-cherry
86-grape
87-cherry
88-pear
89-cherry
90-apple
91-kiwi
92-banana
93-kiwi
94-banana
95-melon
96-banana
97-melon
98-pineapple
99-apple
100-pineapple

测试用例：

解题

My方法有点笨

public class Kata {
    public static String subtractSum(int n) {
        do {
            n -= nSum(n);
        } while (n > 100);
        return nSwitch(n);
    }

    public static int nSum(int n) {
        char[] arr = String.valueOf(n).toCharArray();
        int sum = 0;
        for (char i : arr) {
            sum += Integer.parseInt(String.valueOf(i));
        }
        return sum;
    }

    public static String nSwitch(int n) {
        switch (n) {
            case 1: return "kiwi";
            case 2 : return "pear";
            case 3 : return "kiwi";
            case 4 : return "banana";
            case 5 : return "melon";
            case 6 : return "banana";
            case 7 : return "melon";
            case 8 : return "pineapple";
            case 9 : return "apple";
            case 10 : return "pineapple";
            case 11 : return "cucumber";
            case 12 : return "pineapple";
            case 13 : return "cucumber";
            case 14 : return "orange";
            case 15 : return "grape";
            case 16 : return "orange";
            case 17 : return "grape";
            case 18 : return "apple";
            case 19 : return "grape";
            case 20 : return "cherry";
            case 21 : return "pear";
            case 22 : return "cherry";
            case 23 : return "pear";
            case 24 : return "kiwi";
            case 25 : return "banana";
            case 26 : return "kiwi";
            case 27 : return "apple";
            case 28 : return "melon";
            case 29 : return "banana";
            case 30 : return "melon";
            case 31 : return "pineapple";
            case 32 : return "melon";
            case 33 : return "pineapple";
            case 34 : return "cucumber";
            case 35 : return "orange";
            case 36 : return "apple";
            case 37 : return "orange";
            case 38 : return "grape";
            case 39 : return "orange";
            case 40 : return "grape";
            case 41 : return "cherry";
            case 42 : return "pear";
            case 43 : return "cherry";
            case 44 : return "pear";
            case 45 : return "apple";
            case 46 : return "pear";
            case 47 : return "kiwi";
            case 48 : return "banana";
            case 49 : return "kiwi";
            case 50 : return "banana";
            case 51 : return "melon";
            case 52 : return "pineapple";
            case 53 : return "melon";
            case 54 : return "apple";
            case 55 : return "cucumber";
            case 56 : return "pineapple";
            case 57 : return "cucumber";
            case 58 : return "orange";
            case 59 : return "cucumber";
            case 60 : return "orange";
            case 61 : return "grape";
            case 62 : return "cherry";
            case 63 : return "apple";
            case 64 : return "cherry";
            case 65 : return "pear";
            case 66 : return "cherry";
            case 67 : return "pear";
            case 68 : return "kiwi";
            case 69 : return "pear";
            case 70 : return "kiwi";
            case 71 : return "banana";
            case 72 : return "apple";
            case 73 : return "banana";
            case 74 : return "melon";
            case 75 : return "pineapple";
            case 76 : return "melon";
            case 77 : return "pineapple";
            case 78 : return "cucumber";
            case 79 : return "pineapple";
            case 80 : return "cucumber";
            case 81 : return "apple";
            case 82 : return "grape";
            case 83 : return "orange";
            case 84 : return "grape";
            case 85 : return "cherry";
            case 86 : return "grape";
            case 87 : return "cherry";
            case 88 : return "pear";
            case 89 : return "cherry";
            case 90 : return "apple";
            case 91 : return "kiwi";
            case 92 : return "banana";
            case 93 : return "kiwi";
            case 94 : return "banana";
            case 95 : return "melon";
            case 96 : return "banana";
            case 97 : return "melon";
            case 98 : return "pineapple";
            case 99 : return "apple";
            case 100 : return "pineapple";
            default: return "";
        }
    }
}

Other

public class Kata {
  public static String subtractSum (int n) {
    return "apple";
  }
}

后记

我的天，这道题原来是脑筋急转弯。