POJ 2778 DNA Sequence (ac automata + Matrix fast Power)

Topic Link: DNA Sequence

Analysis: AC automata + matrix acceleration (fast power).

The idea of a state transfer diagram for an AC automaton at this time is very thorough, and the AC automata is the ability to determine the transfer of the state.

AC Code:

#include <iostream> #include <cstdio> #include <queue> #include <cstring>using namespace std;    const int MOD = 100000;struct matrix{int mat[110][110], n;        Matrix () {} matrix (int _n) {n = _n;    for (int i = 0, i < n; i++) for (int j = 0; J < N; j + +) Mat[i][j] = 0;        } Matrix operator * (const matrix &AMP;B) const{MATRIX ret = Matrix (n);                    for (int i = 0, i < n; i++) for (int j = 0; J < N; j + +) for (int k = 0; k < n; k++) {                    int tmp = (long Long) mat[i][k] * B.mat[k][j]% MOD;                RET.MAT[I][J] = (Ret.mat[i][j] + tmp)% MOD;    } return ret;    }};struct trie{int next[110][4], fail[110];    BOOL end[110];    int root, L;        int NewNode () {for (int i = 0; i < 4; i++) next[l][i] = 1;        end[l++] = false;    return L-1;        } void Init () {L = 0;    root = NewNode (); } int getch (char ch){if (ch = = ' A ') return 0;        if (ch = = ' C ') return 1;        if (ch = = ' G ') return 2;    else return 3;        } void Insert (char s[]) {int len = strlen (s);        int now = root; for (int i = 0; i < len; i++) {if (Next[now][getch (s[i])] = = 1) next[now][getch (s[i]) = Newno            De ();        now = Next[now][getch (S[i]);    } End[now] = true;        } void Build () {queue<int> Q;            for (int i = 0; i < 4; 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 now = Q.front ();            Q.pop ();            if (end[fail[now]] = = true) End[now] = true; for (int i = 0; i < 4; i + +) {if (next[now][i] = = 1) next[now][i] = next[Fail[now] [                I]; else{fail[Next[noW][i]] = next[Fail[now]][i];                Q.push (Next[now][i]);        }}}} Matrix Getmatrix () {Matrix ret = matrix (L);                    for (int i = 0; i < L; i + +) for (int j = 0; J < 4; j + +) if (end[next[i][j] = = False)        ret.mat[i][Next[i][j]] + +;    return ret; }}; Trie Ac;char buf[20];    Matrix Pow_mat (Matrix A, int n) {//fast power MATRIX ret = matrix (A.N);    for (int i = 0; i < RET.N; i + +) ret.mat[i][i] = 1;    Matrix tmp = A;        while (n) {if (N & 1) ret = RET * TMP;        TMP = TMP * TMP;    n >>= 1; } return ret;}    int main () {#ifdef sxk freopen ("In.txt", "R", stdin);    #endif//sxk int n, m;        while (scanf ("%d%d", &m, &n) = = 2) {ac.init ();            for (int i = 0; i < m; i + +) {scanf ("%s", buf);        Ac.insert (BUF);        } ac.build ();        Matrix a = Ac.getmatrix ();      A = Pow_mat (A, n);  int ans = 0;        for (int i = 0; i < A.N; i + +) ans = (ans + a.mat[0][i])% MOD;    printf ("%d\n", ans); } return 0;}

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

POJ 2778 DNA Sequence (ac automata + Matrix fast Power)