codeforces 691A A. Fashion in Berland(水题)

题目链接：

A. Fashion in Berland

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<'0'||CH>'9';F= CH=='-',CH=getchar());
    for(num=0;CH>='0'&&CH<='9';num=num*10+CH-'0',CH=getchar());
    F && (num=-num);
}
int stk[70], tp;
template<class T> inline void print(T p) {
    if(!p) { puts("0"); return; }
    while(p) stk[++ tp] = p%10, p/=10;
    while(tp) putchar(stk[tp--] + '0');
    putchar('\n');
}

//const LL mod=1e9+7;
const double PI=acos(-1.0);
const LL inf=1e18;
const int N=2e5+10;
const int maxn=1005;
const double eps=1e-10;


int n,a[1010];

int main()
{
          read(n);
      int sum=0;
      For(i,1,n)
      {
        read(a[i]);
        sum+=a[i];
      }
      if(n==1)
      {
        if(a[1]==1)
        cout<<"YES";
        else cout<<"NO";
      }
      else {if(sum==n-1)cout<<"YES";
      else cout<<"NO";
    }
        return 0;
}