p1315构建双塔 dp

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<cmath>
 5 #include<algorithm>
 6 using namespace std;
 7 int n;
 8 int a[110]={};
 9 int f[110][2010]={};
10 int sum[110]={};
11 int sumn=0;
12 int main(){
13     cin>>n;
14     for(int i=1;i<=n;i++){
15         cin>>a[i];
16         sumn+=a[i];
17         sum[i]=sumn;
18     }
19     for(int i=0;i<=sumn;i++){
20         f[0][i]=-1;
21     }
22     f[0][0]=0;
23     for(int i=1;i<=n;i++){
24         for(int j=0;j<=sumn;j++){
25             f[i][j]=f[i-1][j];
26             if(j>=a[i]&&f[i-1][j-a[i]]>-1){
27                 f[i][j]=max(f[i][j],f[i-1][j-a[i]]);
28             }
29             if(a[i]>j&&f[i-1][a[i]-j]>-1){
30                 f[i][j]=max(f[i][j],f[i-1][a[i]-j]+a[i]-j);
31             }
32             if(j+a[i]<=sumn&&f[i-1][a[i]+j]>-1){
33                 f[i][j]=max(f[i][j],f[i-1][a[i]+j]+a[i]);
34             }
35         }
36     }
37     if(f[n][0]>0){
38         cout<<f[n][0]<<endl;
39     }
40     else{
41         cout<<"Impossible"<<endl;
42     }
43     return 0;
44 }