HDU 5800 to My girlfriend

Title: To My Girlfriend

Links:http://acm.hdu.edu.cn/showproblem.php?pid=5800

Test instructions

Give you n, S, next n number, define F (i, J, K, L, m) to indicate the required for subscript I, J, K, L, and a subset of M.

　　

　　Then the value of the equation is calculated.

Ideas:

Just beginning to think of the number of I and less than equal to a subset of S, defined dp[i][j] represents the number of I, and the case of J, no matter how optimized or dead to n^3 level. Read the puzzle, only awakened ...

Definition DP[I][J][II][JJ] means: The number of the first I, and to achieve the j,ii required, JJ a must not select the case quantity. II, JJ Range is 0-2, four-cycle can be.

Divided into two types:

1. The number of I may not be selected, then DP[I][J][II][JJ] + + DP[I-1][J][II][JJ] + DP[I-1][J-A[I]][II][JJ].

2. There are two types of:

1. The number of I must be selected, DP[I][J][II][JJ] + = DP[I-1][J-A[I]][II-1][JJ].

2. The number of I must not be selected, DP[I][J][II][JJ] + = dp[i-1][j][ii][jj-1].

AC Code:

1#include <stdio.h>2#include <string.h>3 #defineMod 10000000074typedefLong LongLL;5 inta[1010];6 intdp[1010][1010][3][3];7 voidAddint&x,inty)8 {9x=x+y;Ten   if(X>=mod) x-=Mod; One } A intMain () - { -   intt,n,m; thescanf"%d",&t); -    while(t--) -   { -scanf"%d%d",&n,&m); +      for(intI=1; i<=n;i++) scanf ("%d",&a[i]); -Memset (DP,0,sizeof(DP)); +dp[0][0][0][0]=1; A      for(intI=1; i<=n;i++) at     { -        for(intj=m;j>=0; j--) -       { -          for(intIi=2; ii>=0; ii--) -         { -            for(intjj=2; jj>=0; jj--) in           { -Add (DP[I][J][II][JJ], dp[i-1][J][II][JJ]); to             if(j+a[i]<=m) Add (DP[I][J+A[I]][II][JJ], dp[i-1][J][II][JJ]); +             if(ii >0&& j+a[i]<=m) Add (DP[I][J+A[I]][II][JJ], dp[i-1][j][ii-1][JJ]); -             if(JJ >0) Add (DP[I][J][II][JJ], dp[i-1][j][ii][jj-1] ); the           } *         } $       }Panax Notoginseng     } -LL ret=0; the      for(intI=2; i<=m;i++) +     { Aret=ret+dp[n][i][2][2]; the     } +printf"%i64d\n", ret*2*2%Mod); -   } $   return 0; $}

HDU 5800 to My girlfriend