取数游戏II

传送门

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define re register
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define P pair<int,int>
const int N=1e4;
const int mod=1e9+;
void read(int &a)
{
    a=;
    int d=;
    char ch;
    while(ch=getchar(),ch>''||ch<'')
        if(ch=='-')
            d=-;
    a=ch-'';
    while(ch=getchar(),ch>=''&&ch<='')
        a=a*+ch-'';
    a*=d;
}
void write(int x)
{
    if(x<)
        putchar(),x=-x;
    if(x>)
        write(x/);
    putchar(x%+'');
}
int a[];
int main()
{
    int n;
    read(n);
    int cur;
    for(re int i=;i<=n;i++)
        read(a[i]);
    int t1=,t2=;
    for(re int i=;i<=n;i++)
    {
        if(a[i]==)
            break;
        t1++;
    }
    for(re int i=n;i>=;i--)
    {
        if(a[i]==)
            break;
        t2++;
    }
    if(t1&||t2&)
        puts("YES");
    else
        puts("NO");
    return ;
}