矩阵乘法模板

#include<cstdio>

#include<cstdlib>

#include<cstring>

#include<algorithm>

using namespace std;



const int inf = 0x3f3f3f3f;

const int N = 101;



int n, m; 

struct Matrix{

    int mat[N][N];

    Matrix(){

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

    }

    void input(){

        for(int i = 0; i < m; i++)

            for(int j = 0; j < m; j++)

                scanf("%d",&mat[i][j] );

    }    

    void unit(){

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

        for(int i = 0; i < m; i++) mat[i][i] = 1;

    } 

    Matrix& operator = (const Matrix &a){

        memcpy( mat, a.mat, sizeof(a.mat));

        return *this;

    } 

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

        Matrix res; 

        for(int i = 0; i < m; i++)

            for(int k = 0; k < m; k++)

                if( a.mat[i][k] )

                    for(int j = 0; j < m; j++)

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

        return res;

    }

    friend bool operator == (const Matrix &a, const Matrix &b){

        for(int i = 0; i < m; i++)

            for(int j = 0; j < m; j++)

                if( a.mat[i][j] != b.mat[i][j] ) return false;

        return true;

    }  

    friend Matrix operator ^ (Matrix a,int k){

        Matrix res; res.unit();

        Matrix x; memcpy( x.mat, a.mat, sizeof(a.mat));

        while(k){

            if( k&1 ) res = res*x;

            x = x*x; k >>= 1;    

        }    

        return res;

    } 

};



int dis[N][N];

Matrix A[N];



void floyd(){

    for(int k = 0; k < n; k++)

    for(int i = 0; i < n; i++) 

    if( dis[i][k] != inf )

    for(int j = 0; j < n; j++)

    if( dis[i][j] > dis[i][k] + dis[k][j] )

    dis[i][j] = dis[i][k] + dis[k][j]; 

}

int main(){

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

        for(int i = 0; i < n; i++)

            A[i].input();

        memset(dis, 0x3f, sizeof(dis));

        for(int i = 0; i < n; i++)

            for(int j = 0; j < n; j++){

                Matrix t = A[i]*A[j];

                for(int k = 0; k < n; k++)

                    if( t == A[k] && (k!=i && k!=j) )//不明觉厉... 

                        dis[i][k] = 1;

            }

        floyd();

        

        int a, b, k;scanf("%d", &k);

        for(int i = 0; i < k; i++){

            scanf("%d%d",&a,&b);

            if( dis[a-1][b-1] == inf ) printf("Sorry\n");

            else     printf("%d\n", dis[a-1][b-1] );    

        }

        

    } 

    return 0;

}