题目链接:
题意:
思路:
AC代码:
//#include <bits/stdc++.h>
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>using namespace std;#define For(i,j,n) for(int i=j;i<=n;i++)
#define mst(ss,b) memset(ss,b,sizeof(ss));typedef long long LL;template<class T> void read(T&num) {
char CH; bool F=false;
for(CH=getchar();CH<''||CH>'';F= CH=='-',CH=getchar());
for(num=;CH>=''&&CH<='';num=num*+CH-'',CH=getchar());
F && (num=-num);
}
int stk[], tp;
template<class T> inline void print(T p) {
if(!p) { puts(""); return; }
while(p) stk[++ tp] = p%, p/=;
while(tp) putchar(stk[tp--] + '');
putchar('\n');
}//const LL mod=1e9+7;
const double PI=acos(-1.0);
const LL inf=1e18;
const int N=2e5+;
const int maxn=;
const double eps=1e-;int n,a[];int main()
{
read(n);
int sum=;
For(i,,n)
{
read(a[i]);
sum+=a[i];
}
if(n==)
{
if(a[]==)
cout<<"YES";
else cout<<"NO";
}
else {if(sum==n-)cout<<"YES";
else cout<<"NO";
}
return ;
}