bzoj4698

时间:2024-05-27 19:05:14

题解:

后缀数组

对所有序列差分一下

公共串的长度+1就是答案了

二分 扫一遍height即可,..

代码:

#include <bits/stdc++.h>
using namespace std;
const int N=,M=;
int n,mn=2e9,mx=,lt,rt=2e9,mid,ans=,a[N][N],l[N],b[M],id[M];
int tot,vis[N],cnt,sa[M],ta[M],rk[M],ht[M],wa[M],wb[M],ca[M],cb[M];
int check(int k)
{
for (int i=;i<=tot;i++)
{
if (ht[i]<k)
{
memset(vis,,sizeof(vis));
cnt=;
}
if (!vis[id[sa[i]]])vis[id[sa[i]]]=,++cnt;
if (cnt==n)return ;
}
return ;
}
int main()
{
scanf("%d",&n);
for (int i=;i<=n;i++)
{
scanf("%d",l[i]);
for (int j=;j<=l[i];j++)
{
scanf("%d",&a[i][j]);
if (j>)mx=max(mx,a[i][j]-a[i][j-]);
}
rt=min(rt,l[i]);
}
for (int i=;i<=n;i++)
{
for (int j=;j<=l[i];j++)
{
b[++tot]=a[i][j]-a[i][j-];
id[tot]=i;
}
b[++tot]=++mx;
}
for (int i=;i<=tot;i++)mn=min(mn,b[i]);
for (int i=;i<=tot;i++)b[i]=b[i]-mn+,mx=max(mx,b[i]);
memset(ca,,sizeof(ca));
for (int i=;i<=tot;i++)ca[b[i]]++;
for (int i=;i<=mx;i++)ca[i]+=ca[i-];
for (int i=tot;i>=;i--)sa[ca[b[i]]--]=i;
rk[sa[]]=;
for (int i=;i<=tot;i++)rk[sa[i]]=rk[sa[i-]]+(b[sa[i]]!=b[sa[i-]]);
for (int k=;rk[sa[tot]]<tot;k<<=)
{
memset(ca,,sizeof(ca));
memset(cb,,sizeof(cb));
for (int i=;i<=tot;i++)
{
ca[wa[i]=rk[i]]++;
cb[wb[i]=i+k<=tot?rk[i+k]:]++;
}
for (int i=;i<=tot;i++)
{
ca[i]+=ca[i-];
cb[i]+=cb[i-];
}
for (int i=tot;i;i--)ta[cb[wb[i]]--]=i;
for (int i=tot;i;i--)sa[ca[wa[ta[i]]]--]=ta[i];
rk[sa[]]=;
for (int i=;i<=tot;i++)
rk[sa[i]]=rk[sa[i-]]+(wa[sa[i]]!=wa[sa[i-]]||wb[sa[i]]!=wb[sa[i-]]);
}
for (int i=,j=;i<=tot;i++)
{
if (j)j--;
while (b[i+j]==b[sa[rk[i]-]+j])j++;
ht[rk[i]]=j;
}
while (lt<=rt)
{
if (check(mid=(lt+rt)>>))ans=mid+,lt=mid+;
else rt=mid-;
}
printf("%d\n",ans);
}

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