UVA - 1076 || LA 4126 Password Suspects （AC自动机 + 状压DP + 打印解）

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
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <queue>
#include <string>
#include <vector>
using namespace std;

const int maxn = 100 + 2;

struct Trie{
    int L, root;
    int next[maxn][26];
    int fail[maxn];
    int flag[maxn];
    long long dp[26][maxn][ (1<<10)+2 ];

    void init(){
        L = 0;
        root = newnode();
    }

    int newnode(){
        for (int i = 0; i < 26; ++i){
            next[L][i] = -1;
        }
        flag[L] = 0;
        return L++;
    }


    void insert(char* s,int ii){
        int len = strlen(s);
        int nod = root;
        for (int i = 0; i < len; ++i){
            int id = s[i] - 'a';
            if (next[nod][id] == -1){
                next[nod][id] = newnode();
            }
            nod = next[nod][id];
        }
        flag[nod] = ii;
    }

    void bfs(){
        queue<int>q;

        fail[root] = root;

        for (int i = 0; i < 26; ++i){
            if (next[root][i] == -1){
                next[root][i] = root;
            }
            else {
                fail[next[root][i] ] = root;
                q.push(next[root][i]);
            }

        }


        while(!q.empty()){
            int u = q.front(); q.pop();
            flag[u] |= flag[fail[u] ];
            for (int i = 0; i < 26; ++i){
                if (next[u][i] == -1){
                    next[u][i] = next[fail[u] ][i];
                }
                else {
                    fail[next[u][i] ] = next[fail[u] ][i];
                    q.push(next[u][i]);
                }
            }
        }
    }

    vector<string>v;
    long long dfs(int i, int j, int k,int n,int m){
        long long& ans = dp[i][j][k];
        if (ans != -1) return ans;
        if (i == n){
            if (k == (1<<m) - 1){
                return ans = 1;
            }
            return ans = 0;
        }
        ans = 0;
        for (int l = 0; l < 26; ++l){
            int nx = next[j][l];
            char ch = 'a' + l;
            ans += dfs(i+1, nx, k | flag[nx],  n, m);
        }
        return ans;
    }

    void find(int i,int j,int k, string p, int n, int m){
        if (i >= n){
            if (k == (1<<m) - 1){
                v.push_back(p);
            }
            return;
        }
        if (dp[i][j][k] <= 0) return;

        for (int l = 0; l < 26; ++l){
            int nx = next[j][l];
            char ch = l + 'a';
            find(i+1, nx, k | flag[nx], p + ch, n, m);
        }

    }
    void solve(int n, int m){
        v.clear();
        memset(dp,-1,sizeof dp);
        long long ans = dfs(0,0,0,n, m);
        printf("%lld suspectsn", ans);
        if (ans <= 42){
            find(0,0,0,"", n, m);
            for (int i = 0; i < v.size(); ++i){
                printf("%sn", v[i].c_str());
            }
        }
    }
}ac;
/**
4 1
hee

**/

int n, m;
char s[11][maxn];
int state[11];
int main(){
    int ks = 0;
    while(~scanf("%d %d",&n, &m)){
        if (n == 0 && m == 0) break;
        ac.init();
        for (int i = 0; i < m; ++i){
            scanf("%s", s[i]);
            state[i] = 0;
        }
        for (int i = 0; i < m; ++i){
            for (int j = 0; j < m; ++j){
                if (!strcmp(s[i], s[j])){
                    state[i] |= (1<<j);
                }
            }
        }
        for (int i = 0; i < m; ++i){
            ac.insert(s[i], state[i]);
        }
        ac.bfs();
        printf("Case %d: ",++ks);
        ac.solve(n, m);
    }
    return 0;
}