题解:
和poj1226差不多
把翻转去掉
然后不要忘记开大数组和二分的上限答案
代码:
#include<bits/stdc++.h> using namespace std; typedef long long LL; const int N=100005; char str[N]; int r[N],len,n,t,Index[N],Rank[N],height[N],sa[N],wa[N],wb[N],wv[N],WS[N]; int cmp(int *r,int a,int b,int l) { return r[a]==r[b]&&r[a+l]==r[b+l]; } void da(int *r,int *sa,int n,int m) { int p,*x=wa,*y=wb,*t; for (int i=0;i<m;i++)WS[i]=0; for (int i=0;i<n;i++)WS[x[i]=r[i]]++; for (int i=1;i<m;i++)WS[i]+=WS[i-1]; for (int i=n-1;i>=0;i--)sa[--WS[x[i]]]=i; for (int j=1,p=1;p<n;j*=2,m=p) { p=0; for (int i=n-j;i<n;i++)y[p++]=i; for (int i=0;i<n;i++) if (sa[i]>=j)y[p++]=sa[i]-j; for (int i=0;i<n;i++)wv[i]=x[y[i]]; for (int i=0;i<m;i++)WS[i]=0; for (int i=0;i<n;i++)WS[wv[i]]++; for (int i=1;i<m;i++)WS[i]+=WS[i-1]; for (int i=n-1;i>=0;i--)sa[--WS[wv[i]]]=y[i]; t=x,x=y,y=t,p=1,x[sa[0]]=0; for (int i=1;i<n;i++) x[sa[i]]=cmp(y,sa[i-1],sa[i],j)?p-1:p++; } return; } void calheight(int *r,int *sa,int n) { int k=0; for (int i=1;i<=n;i++)Rank[sa[i]]=i; for (int i=0;i<n;height[Rank[i++]]=k) { k?k--:0; for (int j=sa[Rank[i]-1];r[i+k]==r[j+k];k++); } return; } int check(int x) { set<int>se; for (int i=1;i<len;i++) { if (height[i]>=x) { se.insert(Index[sa[i]]); se.insert(Index[sa[i-1]]); } else { if (se.size()==n)return 1; se.clear(); } } if (se.size()==n)return 1; return false; } void solve() { int L=1,R=2005,ans=0; while (R>=L) { int mid=(L+R)/2; if (check(mid)) { ans=mid; L=mid+1; } else R=mid-1; } printf("%d\n",ans); } int main() { scanf("%d",&n); for (int i=1,val=0;i<=n;i++) { scanf("%s",&str); for (int j=0;j<strlen(str);j++) { Index[len]=i; r[len++]=(str[j]-'a'+2*n+1); } Index[len]=i; r[len++]=val++; } da(r,sa,len,300); calheight(r,sa,len-1); solve(); return 0; }