【nowcoder】 4th T2 区间

题目链接：https://www.nowcoder.com/acm/contest/175/B

当你为时间复杂度挠头的时候 别人已经33行拿满分了

 #include<cstdio>
 #include<algorithm>
 #define N 4000010
 using namespace std;
 typedef long long ll;

 ll Read(){
     ll xx=,ff=;char ch=getchar();
     while(ch>''||ch<'') {if(ch=='-') ff=-;ch=getchar();}
     while(ch<=''&&ch>='') {xx=(xx<<)+(xx<<)+ch-'';ch=getchar();}
     return xx*ff;
 }

 ll n,inp[N];
 int res,ans[N];

 int main(){
     n=Read();
     for(register int i=;i<=n;i++)
     inp[i]=Read();
     for(register int i=,r=;i<=n;++i){
         if(r<i) r=i;
         while(r<n&&inp[r+]%inp[i]==) r++;
         ans[i]=r;
     }
     for(register int i=n,l=n;i>;--i){
         if(l>i) l=i;
         while(l>&&inp[l-]%inp[i]==) l--;
         res=max(res,ans[i]-l+);
     }
     printf("%d",res);
     return ;
 }