Uva 1386 - Cellular Automaton ( 矩阵乘法 + 循环矩阵 )

Uva 1386 - Cellular Automaton ( 矩阵乘法 + 循环矩阵 )

#include <cstdio>
#include <cstring>
#define CLR( a, b ) memset( a, b, sizeof(a) )
int MOD;
#define MAX_SIZE 500

struct Mat
{
    int n;
    LL mat[MAX_SIZE][MAX_SIZE];

    Mat( int _n = 0 )
    {
        n = _n;
        CLR( mat, 0 );
    }
    void init()
    {
        for( int i = 0; i < n; ++i )
            for( int j = 0; j < n; ++j )
                mat[i][j] = ( i == j );
    }
    Mat operator + ( const Mat &b ) const
    {
        Mat t( n );
        for( int i = 0; i < n; ++i )
            for( int j = 0; j < n; ++j )
                t.mat[i][j] = ( mat[i][j] + b.mat[i][j] ) % MOD;
        return t;
    }
    Mat operator * ( const Mat &b ) const
    {
        Mat t( n );
        for( int k = 0; k < n; ++k )
            for( int i = 0; i < n; ++i ) if( mat[i][k] )
                for( int j = 0; j < n; ++j )
                    t.mat[i][j] = ( t.mat[i][j] + mat[i][k] * b.mat[k][j] ) % MOD;
        return t;

    }
    void debug()
    {
        for( int i = 0; i < n; ++i )
        {
            for( int j = 0; j < n; ++j )
            {
                if( j !=0 )    putchar( ‘ ‘ );
                printf( "%d", mat[i][j] );
            }
            putchar( ‘\n‘ );
        }
    }
};

Mat fast_mod( Mat a, int b )
{
    Mat c( a.n );
    c.init();
    while( b )
    {
        if( b & 1 ) c = c * a;
        a = a * a;
        b >>= 1;
    }
    return c;
}

void scan( int &x )
{
    char c;
    while( c = getchar(), c < ‘0‘ || c > ‘9‘ );
    x = c - ‘0‘;
    while( c = getchar(), c >= ‘0‘ && c <= ‘9‘ )    x = x * 10 + c - ‘0‘;
}

void Orz()
{
    int n, d, k;
    while( ~scanf( "%d %d %d %d", &n, &MOD, &d, &k ) )
    {
        Mat c( n );
        for( int i = 0; i < n; ++i )
            scan( c.mat[i][0] );
        Mat t( n );
        for( int i = 0; i < n; ++i )
        {
            t.mat[i][i] = 1;
            for( int j = 1; j <= d; ++j )
            {
                int t1 = i - j;
                int t2 = i + j;
                if( t1 < 0 ) t1 += n;
                t.mat[i][t1] = 1;
                if( t2 > n-1 )  t2 -= n;
                t.mat[i][t2] = 1;
            }
        }
        //t.debug();
        t = fast_mod( t, k );
        t = t * c;
        for( int i = 0; i < n; ++i )
        {
            if( i != 0 )    putchar( ‘ ‘ );
            printf( "%d", t.mat[i][0] );
        }
        putchar( ‘\n‘ );
    }
}

int main()
{
    Orz();
    return 0;
}

开始写的错误代码

#include <cstdio>
#include <cstring>
#define CLR( a, b ) memset( a, b, sizeof(a) )
#define MAXN 500
typedef long long LL;
int n, d, k, MOD;
LL A[MAXN], B[MAXN];

void mul( LL *a, LL *b )
{
    LL c[MAXN] = {0};
    for( int i = 0; i < n; ++i )
        for( int j = 0; j < n; ++j )
            c[i] += a[j] * b[ i <= j ? ( j - i ) : ( n - i + j ) ];
    for( int i = 0; i < n; ++i )
        a[i] = c[i] % MOD;
}

void fast_mod( int b )
{
    while( b )
    {
        if( b & 1 ) mul( A, B );
        mul( B, B );
        b >>= 1;
    }
}

void scan( LL &x )
{
    char c;
    while( c = getchar(), c < ‘0‘ || c > ‘9‘ );
    x = c - ‘0‘;
    while( c = getchar(), c >= ‘0‘ && c <= ‘9‘ )    x = x * 10 + c - ‘0‘;
}

int main()
{
    while( ~scanf( "%d %d %d %d",&n, &MOD, &d, &k ) )
    {
        CLR( A, 0 ); CLR( B, 0 );
        for( int i = 0; i < n; ++i )
            scan( A[i] );
        for( int i = -d; i <= d; ++i )
            B[( i + n ) % n ] = 1;
        fast_mod( k );
        for( int i = 0; i < n; ++i )
        {
            if( i != 0 ) putchar( ‘ ‘ );
            printf( "%lld", A[i] );
        } 

        putchar( ‘\n‘ );
    }
}

AC代码君-细节的东西自己注意吧