HDU 5464.Clarke and problem-动态规划

Clarke and problem

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 1292    Accepted Submission(s): 532

Problem Description

Clarke is a patient with multiple personality disorder. One day, Clarke turned into a student and read a book.
Suddenly, a difficult problem appears: 
You are given a sequence of number a1,a2,...,an and a number p. Count the number of the way to choose some of number(choose none of them is also a solution) from the sequence that sum of the numbers is a multiple of p(0 is also count as a multiple of p). Since the answer is very large, you only need to output the answer modulo 109+7

 

 

Input

The first line contains one integer T(1≤T≤10) - the number of test cases. 
T test cases follow. 
The first line contains two positive integers n,p(1≤n,p≤1000) 
The second line contains n integers a1,a2,...an(|ai|≤109).

 

 

Output

For each testcase print a integer, the answer.

 

 

Sample Input

1 2 3 1 2

 

 

Sample Output

2 Hint: 2 choice: choose none and choose all.

 

 

Source

BestCoder Round #56 (div.2)

 

 

 

代码:

#include<stdio.h>
#include<string.h>
const int mod=1e9+7;
const int N=1000+10;
int a[N];
int dp[N][N];
int main(){
    int t,n,p;
    while(~scanf("%d",&t)){
        while(t--){
            scanf("%d%d",&n,&p);
            for(int i=1;i<=n;i++){
                scanf("%d",&a[i]);
                a[i]=(a[i]%p+p)%p;
            }
            dp[0][0]=1;
            for(int i=1;i<=n;i++){
                for(int j=0;j<=p-1;j++){
                    dp[i][j]=(dp[i-1][j]+dp[i-1][(j-a[i]+p)%p])%mod;
                }
            }
            printf("%d\n",dp[n][0]%mod);
        }
    }
    return 0;
}