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POJ3420 Quad Tiling (矩阵加速状压dp)
传送门:http://poj.org/problem?id=3420
Quad Tiling
Time Limit: 1000MS | Memory Limit: 65536K | |
Description
Tired of the Tri Tiling game finally, Michael turns to a more challengeable game, Quad Tiling:
In how many ways can you tile a 4 × N (1 ≤ N ≤ 109) rectangle with 2 × 1 dominoes? For the answer would be very big, output the answer modulo M (0 < M ≤ 105).
Input
Input consists of several test cases followed by a line containing double 0. Each test case consists of two integers, N and M, respectively.
Output
For each test case, output the answer modules M.
Sample Input
1 100003 100005 100000 0
Sample Output
11195
Source
POJ Monthly--2007.10.06, Dagger
这题是POJ2411的放大版。。记得JSOI2013第一轮考过一题5*N的。。当时cxt还和我炫耀。。现在看看还是很简单的
N=1e9 M=1e5的时候。。需要longlong,不过我侥幸没加longlong过了。。
做法就是开个16*16的矩阵。。不过根据矩阵似乎就可以直接推出来递推式了。。好神orz...
Codes:
1 #include<set> 2 #include<queue> 3 #include<cstdio> 4 #include<cstring> 5 #include<cstdlib> 6 #include<iostream> 7 #include<algorithm> 8 using namespace std; 9 #define For(i,n) for(int i=1;i<=n;i++)10 #define Rep(i,l,r) for(int i=l;i<=r;i++)11 12 struct Matrix{13 int A[17][17];14 Matrix(){15 memset(A,0,sizeof(A));16 }17 }Unit,Ans,TAns;18 19 int opt[20],n,Mod;20 21 Matrix operator * (Matrix A,Matrix B){22 Matrix C;23 Rep(i,0,15)24 Rep(j,0,15)25 Rep(k,0,15)26 C.A[i][j] = ( C.A[i][j] + (A.A[i][k] * B.A[k][j]) % Mod ) % Mod;27 return C;28 }29 30 bool Check(int s1,int s2){31 if((s1|s2)!=15) return false;32 for(int i=0;i<=15;){33 if( (s1&(1<<i)) != (s2&(1<<i)) ) i++;34 else{35 if(i==15) return false; else36 if( ( s1 & (1<<(i+1)) ) != ( s2 & (1<<(i+1)) ) ) return false;37 i+=2;38 }39 }40 return true;41 }42 43 int main(){44 Rep(i,0,15){45 Rep(j,0,15)46 if(Check(i,j)) Ans.A[i][j] = TAns.A[i][j] = 1;47 if(Check(i,15)) 48 opt[i] = 1;49 }50 while(scanf("%d%d",&n,&Mod),Mod+n){ 51 Rep(i,0,15){52 Rep(j,0,15){53 Ans.A[i][j] = TAns.A[i][j];54 Unit.A[i][j] = 0;55 }56 Unit.A[i][i] = 1;57 } 58 while(n){59 if(n&1) Unit = Unit * Ans;60 Ans = Ans * Ans;61 n = n >> 1;62 }63 int ans = 0;64 Rep(i,0,15) 65 ans = (ans % Mod + (opt[i] * Unit.A[0][i] % Mod) % Mod) % Mod;66 printf("%d\n",ans);67 }68 return 0;69 }
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