POJ 3628 Bookshelf 2

 1 #include<stdio.h>
 2 #include<string.h>
 3 int w[100],f[20000000];
 4 int max(int a,int b)
 5 {
 6     return a>b?a:b;
 7 }
 8 int main()
 9 {
10     int n,b,i,j;
11     int sum=0;
12     while(scanf("%d%d",&n,&b)!=EOF)
13     {
14         for(i=0;i<=n;i++)
15             f[i]=0;
16         sum=0;
17         for(i=0; i<n; i++)
18         {
19             scanf("%d",&w[i]);
20             sum+=w[i];
21         }
22         int k=sum-b;
23         for(i=0; i<n; i++)
24         {
25             for(j=k; j>=w[i]; j--)
26             {
27                 f[j]=max(f[j],f[j-w[i]]+w[i]);
28             }
29         }
30         printf("%d\n",k-f[k]);
31     }
32     return 0;
33 }

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstdlib>
 4 #include <cstring>
 5 using namespace std;
 6 #define maxn 25
 7 int n, m;
 8 int f[maxn], s[maxn];
 9 int ans;
10 void dfs(int cow, int sum)
11 {
12     if (ans == 0)
13         return;
14     if (s[cow] + sum < m)
15         return;
16     if (sum >= m)
17     {
18         ans = min(ans, sum - m);
19         return;
20     }
21     if (cow == n)
22         return;
23     dfs(cow + 1, sum);
24     dfs(cow + 1, sum + f[cow]);
25 }
26 int main()
27 {
28     scanf("%d%d", &n, &m);
29     for (int i = 0; i < n; i++)
30         scanf("%d", &f[i]);
31     s[n] = 0;
32     for (int i = n - 1; i >= 0; i--)
33         s[i] = s[i + 1] + f[i];
34     ans = 0x3f3f3f3f;
35     dfs(0,0);
36     printf("%d\n", ans);
37     return 0;
38 }