bzoj4547 小奇的集合

 1 #include<cstdio>
 2 #include<cstring>
 3 #include<algorithm>
 4 #define N 200010
 5 #define P 10000007
 6 using namespace std;
 7 typedef long long ll;
 8 int n,k,i,j,t1,t2;
 9 int a[N];
10 long long u,v,w,sum;
11 struct g{
12     long long v[3][3];
13     void clear()
14     {
15         memset(v,0,sizeof(v));
16     }
17 }m,o;
18 g operator *(g a,g b)
19 {
20     g c;c.clear();
21     int i,j,k;
22     for (i=0;i<=2;i++)
23     for (j=0;j<=2;j++)
24     for (k=0;k<=2;k++)
25     c.v[i][j]=(c.v[i][j]+a.v[i][k]*b.v[k][j])%P;
26     return c;
27 }
28 g ksm(int x)
29 {
30     g ans;
31     if (x==1)
32         return o;
33     ans=ksm(x/2);
34     ans=ans*ans;
35     if (x%2)
36     ans=ans*o;
37     return ans;
38 }
39 int main()
40 {
41     a[0]=-2000000000;
42     scanf("%d%d",&n,&k);
43     for(i=1;i<=n;i++)
44     {
45         scanf("%d",&a[i]);
46         sum=(sum+a[i])%P;
47         if (a[i]>a[t1]) t1=i;
48     }
49     for (i=1;i<=n;i++)
50     if ((i!=t1)&&(a[i]>a[t2])) t2=i;
51     u=a[t1];v=a[t2];
52     if ((u<=0)&&(v<=0))
53     {
54         sum=(sum+(u+v)*k)%P;
55     }
56     else
57     {
58         while (((u<=0)||(v<=0))&&(k))
59         {
60             w=u+v;sum=(w+sum)%P;
61             u=max(u,v);v=w;k--;
62         }
63         if (u>v)
64         {
65             w=v;v=u;u=w;
66         }
67         o.clear();
68         o.v[0][1]=o.v[1][0]=o.v[1][1]=1;
69         o.v[2][0]=o.v[2][1]=o.v[2][2]=1;
70         if (k) m=ksm(k);
71         /*
72         for (i=0;i<=2;i++)
73         {
74         for (j=0;j<=2;j++)
75         printf("%d ",m.v[i][j]);
76         printf("\n");
77         }
78         */
79         sum=(sum+u*m.v[2][0]+v*m.v[2][1])%P;
80     }
81     printf("%lld\n",sum);
82 }
83 /*
84 0 1 0
85 1 1 0
86 1 1 1
87 */