hdu----(4301)Divide Chocolate(状态打表)

Divide Chocolate

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 1757    Accepted Submission(s): 827


Problem Description
It is well known that claire likes dessert very much, especially chocolate. But as a girl she also focuses on the intake of calories each day. To satisfy both of the two desires, claire makes a decision that each chocolate should be divided into several parts, and each time she will enjoy only one part of the chocolate. Obviously clever claire can easily accomplish the division, but she is curious about how many ways there are to divide the chocolate.
hdu----(4301)Divide Chocolate(状态打表)_第1张图片

To simplify this problem, the chocolate can be seen as a rectangular contains n*2 grids (see above). And for a legal division plan, each part contains one or more grids that are connected. We say two grids are connected only if they share an edge with each other or they are both connected with a third grid that belongs to the same part. And please note, because of the amazing craft, each grid is different with others, so symmetrical division methods should be seen as different.
 

 

Input
First line of the input contains one integer indicates the number of test cases. For each case, there is a single line containing two integers n (1<=n<=1000) and k (1<=k<=2*n).n denotes the size of the chocolate and k denotes the number of parts claire wants to divide it into.
 

 

Output
For each case please print the answer (the number of different ways to divide the chocolate) module 100000007 in a single line. 
 

 

Sample Input
2 2 1 5 2
 

 

Sample Output
1 45
 

 

Author
BUPT
 

 

Source
 

 

Recommend
     给你一个2*n的矩阵分成k部分的数目求余....
    思路:dp1[n][m]前N列分成M份,最后两个分开的情况数  (看到某位大牛的思路写的...)

             dp2[n][m]前N列分成M份,最后两个在一起断情况

   
代码:
 1 #include<iostream>
 2 #include<cstring>
 3 #include<cstdio>
 4 using namespace std;
 5 typedef long long LL;
 6 const int maxn=2010;
 7 const LL mod=100000007;
 8 LL dp1[1003][maxn],dp2[1003][maxn];
 9 int main()
10 {
11  memset(dp1,0,sizeof(dp1));
12  memset(dp2,0,sizeof(dp2));
13  dp1[1][1]=0;dp1[1][2]=1;
14  dp2[1][1]=1;dp2[1][2]=0;
15  for(int i=2;i<=1002;++i)
16  for(int j=1;j<=i+i;++j)
17  {
18    dp1[i][j]=dp1[i-1][j]+dp1[i-1][j-1]*2+dp2[i-1][j-1]*2;
19    if(j>2)
20    dp1[i][j]+=dp1[i-1][j-2]+dp2[i-1][j-2];
21    dp1[i][j]%=mod;
22    dp2[i][j]=dp1[i-1][j]*2+dp2[i-1][j]+dp1[i-1][j-1]+dp2[i-1][j-1];
23    dp2[i][j]%=mod;
24  }
25    int test;
26     scanf("%d",&test);
27     while(test--){
28      int a,b;
29      scanf("%d%d",&a,&b);
30      printf("%lld\n",(dp1[a][b]+dp2[a][b])%mod);
31     }
32 return 0;
33 }

 

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