3734 Blocks DP 매트릭스 최적화 시작

2371 단어
Blocks
Time Limit: 1000MS
 
Memory Limit: 65536K
Total Submissions: 3665
 
Accepted: 1611
Description
Panda has received an assignment of painting a line of blocks. Since Panda is such an intelligent boy, he starts to think of a math problem of painting. Suppose there are N blocks in a line and each block can be paint red, blue, green or yellow. For some myterious reasons, Panda want both the number of red blocks and green blocks to be even numbers. Under such conditions, Panda wants to know the number of different ways to paint these blocks.
Input
The first line of the input contains an integer T(1≤T≤100), the number of test cases. Each of the next T lines contains an integer N(1≤N≤10^9) indicating the number of blocks.
Output
For each test cases, output the number of ways to paint the blocks in a single line. Since the answer may be quite large, you have to module it by 10007.
Sample Input
2
1
2

Sample Output
2
6
-----
#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
using namespace std;
typedef long long LL;
const int M=10007;
typedef vector<int>vec;
typedef vector<vec>mat;
mat mul(mat &A,mat &B){
    mat C(A.size(),vec(B[0].size()));
    for (int i=0;i<(int)A.size();i++){
        for (int k=0;k<(int)B.size();k++){
            for (int j=0;j<(int)B[0].size();j++){
                C[i][j]=(C[i][j]+A[i][k]*B[k][j])%M;
            }
        }
    }
    return C;
}
mat pow(mat A,LL n){
    mat B(A.size(),vec(A.size()));
    for (int i=0;i<(int)A.size();i++){
        B[i][i]=1;
    }
    while (n>0){
        if (n&1) B=mul(B,A);
        A=mul(A,A);
        n>>=1;
    }
    return B;
}
const int f[3][3]={ {2,1,0},{2,2,2},{0,1,2} };
const int a[1][3]={ {1,0,0} };
int main()
{
    int T;
    scanf("%d",&T);
    while (T--){
        int n;
        scanf("%d",&n);
        mat A(3,vec(3));
        for (int i=0;i<3;i++)
            for (int j=0;j<3;j++)
                A[i][j]=f[i][j];
        A=pow(A,n);
        mat B(1,vec(3));
        for (int i=0;i<3;i++) B[0][i]=a[0][i];
        A=mul(A,B);
        printf("%d
",A[0][0]); } return 0; }

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