【POJ】2278 DNA Sequence

各种wa后，各种TLE。注意若AC非法，则ACT等一定非法。而且尽量少MOD。

#include <iostream>
#include <cstdio>
#include <cstring>
#include <queue>
using namespace std;

#define MAXN 105
#define NXTN 4

char str[15];

typedef struct Matrix {
    int n;
    __int64 map[MAXN][MAXN];
    Matrix() {}
    Matrix(int nn) {
        n = nn;
        for (int i=0; i<nn; ++i)
            for (int j=0; j<nn; ++j)
                map[i][j] = 0;
    }
} Matrix;

int getval(char ch) {
    switch (ch) {
    case 'A': return 0;
    case 'C': return 1;
    case 'T': return 2;
    case 'G': return 3;
    default: return 0;
    }
}

struct AC {
    int next[MAXN][NXTN], fail[MAXN], v[MAXN];
    int n, root;
    void init() {
        n = 0;
        root = newNode();
    }
    int newNode() {
        fail[n] = 0;
        v[n] = 0;
        memset(next[n], -1, sizeof(next[n]));
        return n++;
    }
    void create(char s[]) {
        int i = 0, id;
        int cur = root;

        while (s[i]) {
            id = getval(s[i]);
            ++i;
            if (next[cur][id] == -1)
                next[cur][id] = newNode();
            cur = next[cur][id];
        }
        v[cur] = 1;
    }
    void build() {
        int i, cur;
        queue<int> Q;

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

        while (!Q.empty()) {
            cur = Q.front();
            Q.pop();
            if (v[fail[cur]])    // important
                v[cur] = 1;
            for (i=0; i<NXTN; ++i) {
                if (next[cur][i] == -1)
                    next[cur][i] = next[fail[cur]][i];
                else {
                    fail[next[cur][i]] = next[fail[cur]][i];
                    Q.push(next[cur][i]);
                }
            }
        }
    }
    Matrix query() {
        int i, j;

        Matrix mat(n);

        for (i=0; i<n; ++i) {
            for (j=0; j<NXTN; ++j) {
                if (v[next[i][j]] == 0)
                    ++mat.map[i][next[i][j]];
            }
        }
        return mat;
    }
};

AC ac;

Matrix mmul(Matrix a, Matrix b) {
    int i, j, k, n = a.n;
    Matrix ret(n);

    for (i=0; i<n; ++i)
        for (j=0; j<n; ++j)
            for (k=0; k<n; ++k) {
                ret.map[i][j] += a.map[i][k]*b.map[k][j];
                ret.map[i][j] %= 100000;
            }
    return ret;
}

void mpow(Matrix a, int n) {
    Matrix ret(a.n);
    int i;
    __int64 ans;

    for (i=0; i<ret.n; ++i)
        ret.map[i][i] = 1;

    while (n) {
        if (n & 1)
            ret = mmul(ret, a);
        a = mmul(a, a);
        n >>= 1;
    }

    ans = 0;
    for (i=0; i<ret.n; ++i) {
        //printf("i:%I64d
", ret.map[0][i]);
        ans += ret.map[0][i];
        ans %= 100000;
    }
    printf("%I64d
", ans);
}

int main() {
    int m, n;
    int i;

    while (scanf("%d %d", &m, &n) != EOF) {
        ac.init();
        for (i=0; i<m; ++i) {
            scanf("%s", str);
            ac.create(str);
        }
        ac.build();
        Matrix mat = ac.query();
        //printf("mat.n=%d
", mat.n);
        mpow(mat, n);
    }

    return 0;
}