FilesExpand file tree

 master

/

Code03_AC1.java

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

105 lines (93 loc) · 2.28 KB

 master

/

Code03_AC1.java

Copy path

Top

File metadata and controls

• Code
• Blame

105 lines (93 loc) · 2.28 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

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

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

package class32;

import java.util.LinkedList;

import java.util.Queue;

public class Code03_AC1 {

public static class Node {

public int end; // 有多少个字符串以该节点结尾

public Node fail;

public Node[] nexts;

public Node() {

end = 0;

fail = null;

nexts = new Node[26];

}

}

public static class ACAutomation {

private Node root;

public ACAutomation() {

root = new Node();

}

// 你有多少个匹配串，就调用多少次insert

public void insert(String s) {

char[] str = s.toCharArray();

Node cur = root;

int index = 0;

for (int i = 0; i < str.length; i++) {

index = str[i] - 'a';

if (cur.nexts[index] == null) {

Node next = new Node();

cur.nexts[index] = next;

}

cur = cur.nexts[index];

}

cur.end++;

}

public void build() {

Queue<Node> queue = new LinkedList<>();

queue.add(root);

Node cur = null;

Node cfail = null;

while (!queue.isEmpty()) {

cur = queue.poll(); // 父

for (int i = 0; i < 26; i++) { // 下级所有的路

if (cur.nexts[i] != null) { // 该路下有子节点

cur.nexts[i].fail = root; // 初始时先设置一个值

cfail = cur.fail;

while (cfail != null) { // cur不是头节点

if (cfail.nexts[i] != null) {

cur.nexts[i].fail = cfail.nexts[i];

break;

}

cfail = cfail.fail;

}

queue.add(cur.nexts[i]);

}

}

}

}

public int containNum(String content) {

char[] str = content.toCharArray();

Node cur = root;

Node follow = null;

int index = 0;

int ans = 0;

for (int i = 0; i < str.length; i++) {

index = str[i] - 'a';

while (cur.nexts[index] == null && cur != root) {

cur = cur.fail;

}

cur = cur.nexts[index] != null ? cur.nexts[index] : root;

follow = cur;

while (follow != root) {

if (follow.end == -1) {

break;

}

{ // 不同的需求，在这一段{ }之间修改

ans += follow.end;

follow.end = -1;

} // 不同的需求，在这一段{ }之间修改

follow = follow.fail;

}

}

return ans;

}

}

public static void main(String[] args) {

ACAutomation ac = new ACAutomation();

ac.insert("dhe");

ac.insert("he");

ac.insert("c");

ac.build();

System.out.println(ac.containNum("cdhe"));

}

}