1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include<string.h>
 4 #include<algorithm>
 5 #include<vector>
 6 #include<math.h>
 7 #include<iostream>
 8 #include<functional>
 9 using namespace std;
10 int main()
11 {
12     int n,i;
13     double ans,tol;
14     //freopen("test.in","r",stdin);
15     //freopen("test.out","w",stdout);
16     while(scanf("%d",&n)!=EOF)
17     {
18         vector<int>aa(n+1);
19         for(i=0;i<n;i++)
20             cin>>aa[i];
21      sort(aa.begin(),aa.end(),greater<int>());
22      for(i=3;i<n;i++)
23      {
24          if(aa[0]>aa[1])
25          {
26              if(aa[1]>aa[2])
27                  aa[2]+=aa[i];
28              else
29                  aa[1]+=aa[i];
30          }
31          else
32          {
33              if(aa[0]>aa[2])
34                   aa[2]+=aa[i];
35              else
36                   aa[0]+=aa[i];
37          }
38      }
39           tol=(aa[0]+aa[1]+aa[2])/2.0;
40           ans=(100.0*sqrt(tol*(tol-aa[0])*(tol-aa[1])*(tol-aa[2])));    //o￡?×1?ê?
41      if(ans>1.0e-4)
42               {
43                   printf("%d %d %d\n",aa[0],aa[1],aa[2]);
44                   printf("%.lf\n",floor(ans));
45
46               }
47      else
48           printf("-1\n");
49     }
50     return 0;
51 }

 1 /*
 2 10
 3 1 3 6 9 0 8 5 7 4 2
 4 7 6 5 4 3 2 1 0
 5 1 0
 6 2 1 0
 7 3 2 1 0
 8 4 3 2 1 0
 9 5 4 3 2 1 0
10 6 5 4 3 2 1 0
11 7 6 5 4 3 2 1 0
12 8 7 6 5 4 3 2 1 0
13 9 8 7 6 5 4 3 2 1 0
14 10 9 8 7 6 5 4 3 2 1 0
15 */
16
17 //answer
18 /*
19 9742
20 2121
21 -1
22 -1
23 -1
24 -1
25 447
26 1082
27 2121
28 3741
29 6235
30 9742
31 */

 1 //二维0/1背包
 2 //扩大栈空间
 3 #pragma comment(linker, "/STACK:102400000,102400000")
 4 #include<stdio.h>
 5 #include<math.h>
 6 #include<string.h>
 7 #include<stdlib.h>
 8  int val[41],aa[41];
 9  bool dp[801][801];
10 int main()
11 {
12     int n,i,j,k,ans,len,temp;
13     double cc;
14     freopen("test.in","r",stdin);
15     freopen("test.out","w",stdout);
16     while(scanf("%d",&n)!=EOF)
17     {
18        memset(dp,0,sizeof(dp));
19        memset(aa,0,sizeof(aa));
20       for(i=1;i<=n;i++)
21        {
22          scanf("%d",&val[i]);
23          aa[i]+=aa[i-1]+val[i];
24        }
25         cc=aa[n]/2.0;
26         len=cc;
27         temp=0;
28        dp[0][0]=true;
29        for(i=1;i<=n;i++)
30        {
31            if(len<=aa[i])
32                 temp=len;
33            else temp=aa[i];
34          for(j=temp;j>=0;j--)
35          {
36            for(k=temp;k>=0;k--)
37            {
38               if((j-val[i]>=0&&dp[j-val[i]][k])||(k-val[i]>=0&&dp[j][k-val[i]]))
39                   dp[j][k]=true;
40            }
41          }
42        }
43        ans=0;
44        for(i=1;i<=len;i++)
45        {
46            for(j=1;j<=len;j++)
47            {
48                if(dp[i][j])
49                {
50                  if(ans<100*sqrt(cc*(cc-i)*(cc-j)*(i+j-cc)))
51                     ans=100*sqrt(cc*(cc-i)*(cc-j)*(i+j-cc));
52                }
53            }
54        }
55        if(ans==0)  printf("-1\n");
56         else  printf("%d\n",ans);
57     }
58   return 0;
59 }