Triangular Pastures

#include<cstdio>
#include<cstring>
#include<cmath>
#include<iostream>
using namespace std;
int dp[1000][1000];
int main(){
    int n,res = 0,mx = -1;
    int a[50];
    scanf("%d",&n);
    for(int i = 1; i <= n; i++){
        scanf("%d", &a[i]);
        res+=a[i];}
        int half = res>>1;
    memset(dp,0,sizeof(dp));
    dp[0][0] = 1;
    for(int i = 1; i <= n;i++)
        for(int j = half; j >=0;j--)
            for(int k = j; k >= 0; k--)
                if(j >= a[i]&&dp[j-a[i]][k]||k>=a[i]&&dp[j][k-a[i]])//得到可能性的边
                     dp[j][k] = 1;
        for(int i = half;i >= 1;i--){
            for(int j = i;j >= 1;j--){
                if(dp[i][j]){
                     int k = res - i - j;
                    if(i+j>k && i+k>j&& k+j>i){
                        double p = 1.0*(j+k+i)/2;
                     int S = (int)(sqrt(p*(p-i)*(p-j)*(p-k))*100);
                    if(S>mx)
                        mx = S;
                    }
                }
            }
        }
        printf("%d",mx);
    return 0;
}