2985:数字组合

 1 //*************************************
 2 //7-1   PAx: 620终端
 3 // Name: 2728:摘花生
 4 // Solut:  D.P.
 5 //************************************
 6 #include "stdafx.h"
 7 #include<bits/stdc++.h>
 8 #define N 21
 9 using namespace std;
10 int n, k;
11 int a[N],f[N*N*N];
12 int main()
13 {
14     scanf("%d%d", &n,&k);
15     for (int i = 1; i <= n; i++)
16     {
17         scanf("%d", &a[i]);
18     }
19     f[0] = 1;
20     for (int i = 1; i <= n; i++)
21     {
22         for (int j = k; j >= a[i]; j--)
23         {
24             f[j] += f[j - a[i]];
25         }
26     }
27     printf("%d\n", f[k]);
28     return 0;
29 }