(贪心)度度熊拼三角

Sample Input

3
1 1 100
7
1 9 9 90 2 2 4

Sample Output

-1
22

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
#include<functional>
using namespace std;
typedef long long ll;
const int maxn=1e3+10;
ll a[maxn];
int n;



int main(){
    while(~scanf("%d",&n)){
        for(int i=0;i<n;i++)
            scanf("%d",&a[i]);
        ll ans=-1;
        sort(a,a+n,greater<int>() );
        for(int i=2;i<n;i++){
            ll len=a[i-2]+a[i-1]+a[i];
            ll res=len-a[i-2];
            if(res>a[i-2]){
                ans=len;
                break;
            }
        }
        printf("%lld\n",ans);
    }
    return 0;
}