前端的有限状态机_前端有限状态及

有限状态机 说白了就是根据不同的字符串状态，去归类

function stringMatcher(input) {
  // 定义状态
  const states = {
    START: 'START',
    A: 'A',
    B: 'B',
    REJECT: 'REJECT',
    ACCEPT: 'ACCEPT',
  };

  // 定义状态转换规则
  const transitions = [
    { from: states.START, to: states.A, input: 'a' },
    { from: states.A, to: states.A, input: 'a' },
    { from: states.A, to: states.B, input: 'b' },
    { from: states.B, to: states.B, input: 'b' },
    { from: states.B, to: states.REJECT, input: 'a' },
  ];

  // 初始状态为 START
  let currentState = states.START;

  // 遍历输入字符串
  for (const char of input) {
    let nextState = states.REJECT;
    // 查找下一个状态
    for (const transition of transitions) {
      if (transition.from === currentState && transition.input === char) {
        nextState = transition.to;
        break;
      }
    }
    // 如果没有找到下一个状态，则字符串不符合规则
    if (nextState === states.REJECT) {
      return false;
    }
    currentState = nextState;
  }

  // 如果最终状态是 ACCEPT，则字符串符合规则
  return currentState === states.B;
}

// 测试字符串匹配
console.log(stringMatcher('ab')); // true
console.log(stringMatcher('aaab')); // false
console.log(stringMatcher('abb')); // false
console.log(stringMatcher('abab')); // false
console.log(stringMatcher('')); // false
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49