【贪心+背包】BZOJ1334 [Baltic2008]Elect

 1 #include<cstdio>
 2 #include<algorithm>
 3 #include<cstring>
 4 using namespace std;
 5 const int maxn=1e5+5;
 6 
 7 int a[maxn],f[maxn];
 8 int n,sum,ans;
 9 
10 int main(){
11     scanf("%d",&n);
12     for(int i=1;i<=n;i++)
13         scanf("%d",&a[i]),sum+=a[i];
14     sort(a+1,a+n+1);
15     
16     f[0]=1;
17     for(int i=n;i>=1;i--)
18         for(int j=sum/2+a[i];j>=a[i];j--)
19             if(f[j-a[i]]) f[j]=1,ans=max(j,ans);
20     printf("%d\n",ans);
21     return 0;
22 }