Coding Problem
如果没有三角形，那么数列是斐波拉契数列级别增长，所以个数<50；

#include <iostream>
#include <cmath>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <queue>
#include <string>
#include <stack>
#include <set>
#include <vector>
#include <map>
#define mod 1e9+7
#define inf 0x3f3f3f3f
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
typedef unsigned long long ull;
typedef long long ll;
using namespace std;

const int maxn = 5001000;

int n;
int a[maxn];
int main(){
    int n;
    while(~scanf("%d",&n))
    {
       for(int i=1;i<=n;i++){
        scanf("%d",&a[i]);
    }
    bool flag=false;
    if(n>100){
        cout<<"YES"<<endl;
    }
    else{
            sort(a+1,a+1+n);
        for(int i=1;i<=n-2;i++){
            if(a[i]+a[i+1]>a[i+2]){
                flag=true;
            }
        }
        if(flag){
            cout<<"YES"<<endl;
        }
        else{
            cout<<"NO"<<endl;
        }
    }
    }

    return 0;
}