【HDU】2243 考研路茫茫――单词情结

  1 #include<cstdio>

  2 #include<cstring>

  3 #include<queue>

  4 #define MAXN 26

  5 #define MOD 10330176681277348905LL

  6 typedef unsigned long long LL;

  7 using namespace std;

  8 char str[MAXN];

  9 int size;

 10 LL total, ans;

 11 struct node {

 12     int fail, next[MAXN];

 13     bool end;

 14     void Init() {

 15         end = false;

 16         fail = 0;

 17         memset(next, 0, sizeof(next));

 18     }

 19 };

 20 struct Matrix {

 21     LL mat[MAXN][MAXN];

 22     void Zero() {

 23         memset(mat, 0, sizeof(mat));

 24     }

 25     void Unit() {

 26         int i;

 27         for (i = 0; i <= size; i++)

 28             mat[i][i] = 1;

 29     }

 30 };

 31 Matrix a, b;

 32 node tree[MAXN];

 33 Matrix operator +(const Matrix &a, const Matrix &b) {

 34     int i, j;

 35     Matrix temp;

 36     temp.Zero();

 37     for (i = 0; i <= size; i++) {

 38         for (j = 0; j <= size; j++)

 39             temp.mat[i][j] = a.mat[i][j] + b.mat[i][j];

 40     }

 41     return temp;

 42 }

 43 Matrix operator *(const Matrix &a, const Matrix &b) {

 44     int i, j, k;

 45     Matrix temp;

 46     temp.Zero();

 47     for (i = 0; i <= size; i++) {

 48         for (j = 0; j <= size; j++) {

 49             for (k = 0; k <= size; k++)

 50                 temp.mat[i][j] += a.mat[i][k] * b.mat[k][j];

 51         }

 52     }

 53     return temp;

 54 }

 55 Matrix operator ^(Matrix x, int k) {

 56     Matrix temp;

 57     temp.Zero();

 58     temp.Unit();

 59     for (; k; k >>= 1) {

 60         if (k & 1)

 61             temp = temp * x;

 62         x = x * x;

 63     }

 64     return temp;

 65 }

 66 inline int GET(char ch) {

 67     return ch - 'a';

 68 }

 69 void Insert(char *s) {

 70     int now, t;

 71     for (now = 0; *s; s++) {

 72         t = GET(*s);

 73         if (!tree[now].next[t]) {

 74             tree[++size].Init();

 75             tree[now].next[t] = size;

 76         }

 77         now = tree[now].next[t];

 78     }

 79     tree[now].end = true;

 80 }

 81 void BFS() {

 82     int now, i, p;

 83     queue<int> q;

 84     q.push(0);

 85     while (!q.empty()) {

 86         now = q.front();

 87         q.pop();

 88         for (i = 0; i < MAXN; i++) {

 89             if (tree[now].next[i]) {

 90                 p = tree[now].next[i];

 91                 if (now)

 92                     tree[p].fail = tree[tree[now].fail].next[i];

 93                 tree[p].end |= tree[tree[p].fail].end;

 94                 q.push(p);

 95             } else

 96                 tree[now].next[i] = tree[tree[now].fail].next[i];

 97         }

 98     }

 99 }

100 void GetTotal(int k) {

101     LL temp;

102     total = 1;

103     for (temp = 26; k; k >>= 1) {

104         if (k & 1)

105             total *= temp;

106         temp *= temp;

107     }

108     total = 26 * (total - 1) * MOD;

109 }

110 void Build() {

111     int i, j, p;

112     a.Zero();

113     for (i = 0; i <= size; i++) {

114         if (!tree[i].end) {

115             for (j = 0; j < MAXN; j++) {

116                 p = tree[i].next[j];

117                 if (p) {

118                     if (!tree[p].end)

119                         a.mat[i][p]++;

120                 } else

121                     a.mat[i][0]++;

122             }

123         }

124     }

125 }

126 Matrix DFS(int k) {

127     if (k == 1)

128         return a;

129     if (k & 1)

130         return DFS(k - 1) + (a ^ k);

131     else {

132         Matrix temp = DFS(k >> 1);

133         return temp + ((a ^ (k >> 1)) * temp);

134     }

135 }

136 int main() {

137     int n, m, i;

138     while (~scanf("%d%d", &n, &m)) {

139         GetTotal(m);

140         tree[0].Init();

141         for (i = size = 0; i < n; i++) {

142             scanf(" %s", str);

143             Insert(str);

144         }

145         BFS();

146         Build();

147         b = DFS(m);

148         for (ans = i = 0; i <= size; i++)

149             ans += b.mat[0][i];

150         printf("%I64u\n", total - ans);

151     }

152     return 0;

153 }