2946: [Poi2000]公共串 后缀数组

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define N 11000
#define inf 1000000007
using namespace std;
int n,l,r,ans,len;
int sa
,cc
,height
,rank
,t1
,t2
;
int st[10];
char s
;
bool q[10];
inline bool cmp(int *y,int a,int b,int k)
{
int arank1=y[a];
int brank1=y[b];
int arank2=a+k>=len?-1:y[a+k];
int brank2=b+k>=len?-1:y[b+k];
return arank1==brank1&&arank2==brank2;
}
inline void make_sa()
{
int *x=t1,*y=t2,m=256;
for (int i=0;i<m;i++) cc[i]=0;
for (int i=0;i<len;i++) ++cc[x[i]=s[i]];
for (int i=1;i<m;i++) cc[i]+=cc[i-1];
for (int i=len-1;~i;i--) sa[--cc[x[i]]]=i;
for (int k=1;k<len;k<<=1)
{
int p=0;
for (int i=len-k;i<len;i++) y[p++]=i;
for (int i=0;i<len;i++)
if (sa[i]>=k) y[p++]=sa[i]-k;
for (int i=0;i<m;i++) cc[i]=0;
for (int i=0;i<len;i++) ++cc[x[y[i]]];
for (int i=1;i<m;i++) cc[i]+=cc[i-1];
for (int i=len-1;~i;i--) sa[--cc[x[y[i]]]]=y[i];
swap(x,y); m=1; x[sa[0]]=0;
for (int i=1;i<len;i++)
x[sa[i]]=cmp(y,sa[i-1],sa[i],k)?m-1:m++;
if (m>=len) break;
}
}
inline void make_height()
{
for (int i=0;i<len;i++) rank[sa[i]]=i;
int k=0;
height[0]=0;
for (int i=0;i<len;i++)
{
if (!rank[i]) continue;
int j=sa[rank[i]-1];
if (k) k--;
while (s[i+k]==s[j+k]) k++;
height[rank[i]]=k;
}
}
inline int find(int x)
{
if (s[x]=='&') return 0;
for (int i=2;i<=n;i++)
if (x<st[i]) return i-1;
return n;
}
inline bool judge(int mid)
{
int now=1;
while (now<len)
{
if (height[now]>=mid)
{
memset(q,false,sizeof(q));
q[find(sa[now-1])]=true;
while (height[now]>=mid&&now<len)
{
q[find(sa[now])]=true;
now++;
}
int flag=1;
for (int i=1;i<=n;i++)
if (!q[i])
{
flag=0;
break;
}
if (flag) return true;
}
else now++;
}
return false;
}
int main()
{
scanf("%d",&n); r=inf;
for (int i=1;i<=n;i++)
{
scanf("%s",s+len);
int tmp=strlen(s+len);
len+=tmp;
r=min(r,tmp);
s[len]='&';
st[i+1]=len;
len++;
}
make_sa();
make_height();
while (l<=r)
{
int mid=l+r>>1;
if (judge(mid)) ans=mid,l=mid+1;
else r=mid-1;
}
cout << ans << endl;
return 0;
}