HDU5950

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=5950

解题思路：

　　

AC代码：

 1 #include <cstdio>
 2 #include <cstring>
 3 
 4 using namespace std;
 5 typedef long long ll;
 6 const ll mod=2147493647;
 7 struct Matrix{
 8     ll mat[7][7];
 9 };
10 Matrix cst={1,2,1,4,6,4,1,
11             1,0,0,0,0,0,0,
12             0,0,1,4,6,4,1,
13             0,0,0,1,3,3,1,
14             0,0,0,0,1,2,1,
15             0,0,0,0,0,1,1,
16             0,0,0,0,0,0,1};
17 Matrix Multiply(Matrix x,Matrix y){
18     Matrix temp;
19     memset(temp.mat,0,sizeof(temp.mat));
20     for(int i=0;i<7;i++){
21         for(int j=0;j<7;j++){
22             for(int k=0;k<7;k++){
23                 temp.mat[i][j]+=(x.mat[i][k]*y.mat[k][j]%mod);
24                 temp.mat[i][j]%=mod;
25             }
26         }
27     }
28     return temp;
29 }
30 Matrix Fast_Power(Matrix a,int m){
31     Matrix res;
32     memset(res.mat,0,sizeof(res.mat));
33     for(int i=0;i<7;i++)    res.mat[i][i]=1;
34     while(m){
35         if(m&1) res=Multiply(res,a);
36         m>>=1;
37         a=Multiply(a,a);
38     }
39     return res;
40 }
41 int main(){
42     int t;
43     int N,a,b;
44     scanf("%d",&t);
45     while(t--){
46         scanf("%d%d%d",&N,&a,&b);
47         if(N==1)    printf("%d\n",a);
48         else if(N==2)   printf("%d\n",b);
49         else{
50             Matrix ret=Fast_Power(cst,N-2);
51             ll ans=(ret.mat[0][0]*b%mod+ret.mat[0][1]*a%mod+ret.mat[0][2]*16%mod+ret.mat[0][3]*8%mod+ret.mat[0][4]*4%mod+ret.mat[0][5]*2%mod+ret.mat[0][6]%mod)%mod;
52             printf("%lld\n",ans);
53         }
54     }
55 
56     return 0;
57 }

 

posted @ 2017-09-10 23:15  Blogggggg  阅读(176)  评论(0)  编辑  收藏  举报