Algorithms/ASA(kmp).cpp at main · right9alt/Algorithms · GitHub

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
#include<iostream>
#include<vector>
using namespace std;
void computeLPSArray(char* pat, int M, vector<int> lps);

void KMPSearch(char* pat, char* txt)
{
    int M = strlen(pat);
    int N = strlen(txt);

    vector<int> lps(M);


    computeLPSArray(pat, M, lps);

    int i = 0;
    int j = 0;
    while (i < N) {
        if (pat[j] == txt[i]) {
            j++;
            i++;
        }

        if (j == M) {
            printf("найдено совпадение на индексе %d ", i - j);
            j = lps[j - 1];
        }


        else if (i < N && pat[j] != txt[i]) {

            if (j != 0)
                j = lps[j - 1];
            else
                i = i + 1;
        }
    }
}

void computeLPSArray(char* pat, int M, vector<int> lps)
{

    int len = 0;

    lps[0] = 0;

    int i = 1;
    while (i < M) {
        if (pat[i] == pat[len]) {
            len++;
            lps[i] = len;
            i++;
        }
        else
        {
            if (len != 0) {
                len = lps[len - 1];
            }
            else
            {
                lps[i] = 0;
                i++;
            }
        }
    }
}

int main()
{
    char txt[] = "caccacacabcadb";
    char pat[] = "aca";
    KMPSearch(pat, txt);
    return 0;
}