hdu2254 奥运

来源：互联网发布：java 审批流编辑：程序博客网时间：2024/04/29 02:10

不明白可以去看Matrix大神的矩阵的十种应用去

code：

#include <cstdio>#include <cstring>#include <algorithm>using namespace std;const int MAXN = 31;int city_num,city[MAXN];struct Mat{int mat[MAXN][MAXN];}A,E;Mat operator+ (Mat a,Mat b){Mat res;int i,j;for (i=1;i<=city_num;i++){for(j=1;j<=city_num;j++)res.mat[i][j] = ( a.mat[i][j] + b.mat[i][j] )%2008 ;}return res;}Mat operator* (Mat a,Mat b){int i,j,k;Mat res;for (i=1;i<=city_num;i++){for (j=1;j<=city_num;j++){res.mat[i][j] = 0;for(k=1;k<=city_num;k++)res.mat[i][j]=( res.mat[i][j] + a.mat[i][k]*b.mat[k][j] ) % 2008;}}return res;}Mat operator^ (Mat a,int exp){Mat res = E, tmp = a;while(exp){if(exp&1)res = res * tmp;exp >>= 1;tmp = tmp * tmp;}return res;}int GetCity(int x){int i;for (i=1;i<=city_num;i++){if(city[i]==x)return i;}    city[++city_num] = x;    return city_num;}Mat GetSum(Mat a,int k){if(k==1)return a;if(k&1)return (a^k) + GetSum(a,k-1);    return ((a^(k>>1))+E) * GetSum(a,k>>1);}int main(){int a,b,c,d;int i,j,n,k,sum;Mat tem1,tem2;for(i=1;i<=30;i++)for(j=1;j<=30;j++)E.mat[i][j] = (i==j);while (scanf("%d",&n)!=EOF){city_num = 0;memset(city,-1,sizeof(city));memset(A.mat,0,sizeof(A.mat));while (n--){scanf("%d%d",&a,&b);a = GetCity(a);b = GetCity(b);A.mat[a][b]++;}scanf("%d",&k);while (k--){scanf("%d%d%d%d",&a,&b,&c,&d);if(c>d) swap(c,d);a = GetCity(a);b = GetCity(b);if( c==0&&d==0 || a==-1 || b==-1) puts("0");else{if (c>1)                    printf("%d\n",((GetSum(A,d).mat[a][b]-GetSum(A,c-1).mat[a][b])+2008)%2008);else                    printf("%d\n",GetSum(A,d).mat[a][b]);}}}return 0;}