cf754 A. Lesha and array splitting

 应该是做麻烦了，一开始还没A（幸好上一次比赛水惨了）

#include<bits/stdc++.h>
#define lowbit(x) x&(-x) 
#define LL long long 
#define N 200005
#define M 1000005
#define mod 2147483648LL
#define inf 0x7ffffffff
using namespace std;
inline int ra()
{
    int x=0,f=1; char ch=getchar();
    while (ch<'0' || ch>'9'){if (ch=='-') f=-1; ch=getchar();}
    while (ch>='0' && ch<='9'){x=x*10+ch-'0'; ch=getchar();}
    return x*f;
}
int a[1005];
struct node{
    int x,y;
}ans[1005];
int cnt;
int main()
{
    int n=ra(),start=1;
    bool flag=0;
    for (int i=1; i<=n; i++)
    {
        int x=ra();
        if (x!=0) a[i]=x,flag=1;
    }
    if (!flag) 
    {
        cout<<"NO";
        return 0;
    }
    cout<<"YES"<<endl;
    if (a[1]==0)
    {
        for (int i=1; i<=n; i++)
            if (a[i]!=0) 
            {
                for (int j=i+1; j<=n; j++)
                    if (a[j]!=0 || j==n) 
                    {
                        ans[++cnt].x=1;
                        ans[cnt].y=j-1;
                        start=j;
                        break;
                    }
                break;
            }
        int last=start;
        for (int i=last; i<=n; i++)
        {
            if (i==n && a[i]==0)
                ans[cnt].y=n;
            if (a[i]!=0)
            {
                ans[++cnt].x=start;
                ans[cnt].y=i;
                start=i+1;
            }
        }
    }
    else 
    {
        int last=start;
        for (int i=last; i<=n; i++)
        {
            if (i==n && a[i]==0)
                ans[cnt].y=n;
            if (a[i]!=0)
            {
                ans[++cnt].x=start;
                ans[cnt].y=i;
                start=i+1;
            }
        }
    }
    cout<<cnt<<endl;
    for (int i=1; i<=cnt; i++)
        cout<<ans[i].x<<" "<<ans[i].y<<endl;
    return 0;
}