codeforces/A_Don_t_Try_to_Count.cpp at master · samdani91/codeforces · 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
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
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
#include <bits/stdc++.h>
using namespace std;

typedef long long int ll;
typedef long double ld;
typedef string str;
typedef vector<ll> vll;
typedef vector<string> vs;
typedef vector<pair<ll, ll>> vpl;
typedef set<ll> sll;
typedef map<ll, ll> mll;
typedef pair<int, int> pint;
typedef pair<ll, ll> pll;
double pi = acos(-1.0);
#define debug(x) cerr << #x < < < < x << endl;
#define loop for (ll i = 1; i <= n; i++)
#define all(a) (a).begin(), (a).end()
#define min3(a, b, c) min(a, min(b, c))
#define max3(a, b, c) max(a, max(b, c))
#define min4(a, b, c, d) min(a, min(b, min(c, d)));
#define max4(a, b, c, d) max(a, max(b, max(c, d)));

vector<int> prefixArray(string p)
{
    int n = p.size();
    vector<int> prefix(n, 0);

    int i, j = 0;
    for (i = 1; i < n;)
    {
        if (p[i] == p[j])
        {
            prefix[i] = j + 1;
            j++;
            i++;
        }
        else
        {
            if (j != 0)
            {
                j = prefix[j - 1];
            }
            else
            {
                prefix[i] = 0;
                i++;
            }
        }
    }
    return prefix;
}

bool KMP(string s, string p)
{
    vector<int> prefix = prefixArray(p);
    int i, j;
    i = j = 0;

    int n = s.size();
    int m = p.size();

    while (i < n and j < m)
    {
        if (s[i] == p[j])
        {
            i++;
            j++;
        }

        else if (i < n and s[i] != p[j])
        {
            if (j != 0)
            {
                j = prefix[j - 1];
            }
            else
            {
                i++;
            }
        }
    }
    if (j == m)
    {
        return true;
    }
    else
    {
        return false;
    }
}

int main()
{

    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    int t;
    cin >> t;
    while (t--)
    {
        int n, m;
        cin >> n >> m;
        string x, s;
        cin >> x >> s;
        int count = 0;

        while (1)
        {
            if (x.size() > 25 * s.size())
            {
                cout << -1 << endl;
                break;
            }
            if (x.size() >= s.size() and KMP(x, s))
            {
                cout << count << endl;
                break;
            }
            x += x;
            count++;
        }
    }

    return 0;
}