ARTS 打卡 第 9 周

示例 1：
输入：
  s = "barfoothefoobarman",
  words = ["foo","bar"]
输出：[0,9]
解释：
从索引 0 和 9 开始的子串分别是 "barfoo" 和 "foobar" 。
输出的顺序不重要, [9,0] 也是有效答案。
示例 2：
输入：
  s = "wordgoodgoodgoodbestword",
  words = ["word","good","best","word"]
输出：[]


class Solution {
    public List<Integer> findSubstring(String s, String[] words) {
   List<Integer> ans = new ArrayList<>();
        if (s == null || s.length() == 0 || words == null || words.length == 0) {
            return ans;
        }
        int wordNum = words.length;
        int wordLen = words[0].length();
        HashMap<String, Integer> allWords = new HashMap<>();
        for (String word : words) {
            Integer value = allWords.getOrDefault(word, 0);
            allWords.put(word, ++value);
        }
        //s的剩余必须大于子串长度小于wordNum*wordLen
        int limit = s.length() - wordNum * wordLen;
        for (int i = 0; i <= limit; i++) {
            //将子串中出现的和words中相等的单词及其出现次数存入HashMap
            HashMap<String, Integer> hasWords = new HashMap<>();
            //记录字串中和words中相等单词数量
            int count = 0;
            //统计字串中连续和words中相等的单词
            while (count < wordNum) {
                String wordInS = s.substring(i + count * wordLen, i + (count + 1) * wordLen);
                //如果wordInS匹配words中的单词且不超过可用单词的数量，就统计其出现次数
                if (allWords.containsKey(wordInS)
                        && allWords.get(wordInS) > hasWords.getOrDefault(wordInS, 0)) {
                    Integer value = hasWords.getOrDefault(wordInS, 0);
                    hasWords.put(wordInS, ++value);
                } else {
                    break; //都不匹配，结束
                }
                count++;
            }
            if (count == wordNum) {
                ans.add(i);
            }
        }
        return ans;
    }
}

rm tody.txt
rm：是否删除普通空文件 'tody.txt'？n
# 不加r参数无法删除目录
mkdir md
rm md
rm: 无法删除 'md': 是一个目录
rm -r md
rm：是否删除目录 'md'？y

# 重命名
mv tody.txt todx.txt
# 移动文件到目录中
mv todx.txt subdir/

cp -r test/ newtest

file add.c 
add.c: C source, ASCII text
file -b add.c
C source, ASCII text
file add.o
add.o: ELF 64-bit LSB relocatable, x86-64, version 1 (SYSV), not stripped