2019秋招字节跳动测试开发笔试编程题(原题)

题目一：
猜谜底题目，考察康拓编码
输入：
2
abc
bac
输出：
bac
cba

这个题的意思是：假如输入的为 A = abc,则它的字典全排列为：
[abc, acb , bac , bca ,cab , cba]
那么index(A) = 0,谜底B = index(0+3) = bac

假如输入是为 A = bac, index(A) = 2, 谜底 B = index(5) = cba
如果 index索引超过5，则去index(index - 5)

此题考查康拓编码问题，贴一下自己的代码，没有参加笔试，只是看到了题，在本地写了一下，仅参考~~

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(bf.readLine());
        for (int i = 0; i < n; i++) {
            System.out.println(getResult(bf.readLine()));
        }
    }
    /**
     * 康拓编码
     */
    private static String getResult(String s) {
        int n = s.length();
        int[] jc = new int[n + 1];
        jc[0] = 1;
        ArrayList<Character> list = new ArrayList<>();
        for (int i = 1; i <= n; i++) {
            jc[i] = jc[i - 1] * i;//求阶乘
            list.add(s.charAt(i - 1));
        }
        int index_of_s = 0;//字符串s所在的字典的索引位置
        for (int i = 0; i < n - 1; i++) {
            int count = 0;//比i处小
            for (int j = i + 1; j < n; j++) {
                if (s.charAt(j) < s.charAt(i)) count++;//统计后面有几个数比 i处的小
            }
            index_of_s += jc[n - i - 1] * count;
        }
        // B 的索引位置
        int index = index_of_s + n - (index_of_s + n < jc[n] ? 0 : jc[n]);
        Collections.sort(list);
        int temp = 0;
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < n; i++) {
            temp = index / jc[n - 1 - i];//除数
            index = index - temp * jc[n - i - 1];//余数
            char ch = list.get(temp);
            sb.append(ch);
            list.remove(temp);
        }
        return sb.toString();
    }
}

题目二：
输入两个字符串s1和s2，判断s1是否为包含s2的任意排列。
包含输出 "True"

第二题写的好像有些问题

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        String s1 = bf.readLine();
        String s2 = bf.readLine();
        if (s1.length() < s2.length()) {
            System.out.println("False");
            return;
        }
        if (s2.isEmpty()){
            System.out.println("True");
            return;
        }
        HashMap<Character, Integer> map2 = new HashMap<>();
        for (int i = 0; i < s2.length(); i++) {
            map2.put(s2.charAt(i), map2.getOrDefault(s2.charAt(i), 0) + 1);
        }
        int len = s2.length();
        for (int i = 0; i <= s1.length() - s2.length(); i++) {
            int count = 0;
            for (int j = i; j < i + s2.length(); j++) {
                char c = s1.charAt(j);
                if (map2.containsKey(c) && map2.get(c) > 0) {
                    map2.put(c, map2.get(c) - 1);
                    count++;
                    if (count == s2.length()) {
                        System.out.println("True");
                        return;
                    }
                }else {
                    break;
                }
            }
        }
        System.out.println("False");
    }
}