bzoj 4000 矩阵快速幂优化DP

建立矩阵,跑快速幂

/**************************************************************
    Problem: 4000
    User: idy002
    Language: C++
    Result: Accepted
    Time:32 ms
    Memory:836 kb
****************************************************************/
 
#include <cstdio>
#include <cstring>
#define M 6
 
struct Matrix {
    unsigned v[1<<M][1<<M];
    const unsigned *operator[]( int i ) const { return v[i]; }
};
 
int n, m, p, k, bound;
int attack[3];
int stat[1<<M], id[1<<M], stot;
Matrix base, dest;
 
void make_unit( Matrix &x ) {
    for( int i=0; i<stot; i++ )
        for( int j=0; j<stot; j++ )
            x.v[i][j] = i==j;
}
Matrix operator*( const Matrix &a, const Matrix &b ) {
    Matrix c;
    for( int i=0; i<stot; i++ )
        for( int j=0; j<stot; j++ ) {
            c.v[i][j] = 0;
            for( int k=0; k<stot; k++ )
                c.v[i][j] += a[i][k]*b[k][j];
        }
    return c;
}
Matrix mpow( Matrix a, int b ) {
    Matrix rt;
    for( make_unit(rt); b; b>>=1,a=a*a ) 
        if( b&1 ) rt=rt*a;
    return rt;
}
int getarea( int s, int a ) {
    int rt = 0;
    for( int b=0; b<m; b++ ) {
        if( (s>>b)&1 ) {
            int aa = a;
            if( b<k ) 
                aa >>= k-b;
            else
                aa <<= b-k;
            aa &= bound;
            rt |= aa;
        }
    }
    return rt;
}
void build() {
    stot = 0;
    memset( id, -1, sizeof(id) );
    for( int s=0; s<=bound; s++ ) {
        if( getarea(s,attack[1])&s ) continue;
        stat[stot]=s;
        id[s] = stot;
        stot++;
    }
    for( int s1=0; s1<=bound; s1++ ) {
        if( id[s1]==-1 ) continue;
        for( int s2=0; s2<=bound; s2++ ) {
            if( id[s2]==-1 ) continue;
            if( getarea(s1,attack[2])&s2 ) continue;
            if( getarea(s2,attack[0])&s1 ) continue;
            base.v[id[s1]][id[s2]] = 1;
        }
    }
}
int main() {
    scanf( "%d%d%d%d", &n, &m, &p, &k );
    bound = (1<<m)-1;
    for( int i=0; i<3; i++ )
        for( int j=0,o; j<p; j++ ) {
            scanf( "%d", &o );
            attack[i] = attack[i] | (o<<j);
        }
    attack[1] ^= 1<<k;
    build();
    dest = mpow( base, n-1 );
    unsigned ans = 0;
    for( int i=0; i<stot; i++ )
        for( int j=0; j<stot; j++ )
            ans += dest[i][j];
    printf( "%u
", ans );
}