poj3405 Corporate Identity

和上一个1226一样吧，这个还不用翻转

然而本蒟蒻还是写不对，WA一片天，不知道自己搞什么，自从去了长沙感觉就是坑啊

while(1) iq--;

 /*#include <cstdio>
 #include <iostream>
 #include <cstring>
 #define N 100005
 #define LL long long
 #define eps 1e-8
 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;
 }

 const int M=4233;
 const int maxn=4000*233*3;

 int sa[2][maxn],rank[2][maxn],height[maxn],v[M+5];
 char ans[205];
 int n,len,id[maxn],p,q,a[maxn];
 bool vis[M];

 void cal_sa(int sa[maxn], int rank[maxn], int Sa[maxn], int Rank[maxn], int k)
 {
     for (int i=1; i<=n; i++) v[rank[sa[i]]]=i;
     for (int i=n; i>=1; i--) if (sa[i]>k) Sa[v[rank[sa[i]-k]]--]=sa[i]-k;
     for (int i=n-k+1; i<=n; i++) Sa[v[rank[i]]--]=i;
     for (int i=1; i<=n; i++) Rank[Sa[i]]=Rank[Sa[i-1]]+(rank[Sa[i]]!=rank[Sa[i-1]] || rank[Sa[i]+k]!=rank[Sa[i-1]+k]);
 }
 void get_height()
 {
     int k=0;
     for (int i=1; i<=n; i++)
     {
         if (rank[p][i]==1) height[1]=0;
         else
         {
             int j=sa[p][rank[p][i]-1];
             while (a[j+k]==a[i+k]) k++;
             height[rank[p][i]]=k;
             if (k) k--;
         }
     }
 }
 void work()
 {
     for (int i=1; i<=n; i++) v[a[i]]++;
     for (int i=1; i<=M; i++) v[i]+=v[i-1];
     for (int i=1; i<=n; i++) sa[p][v[a[i]]--]=i;
     for (int i=1; i<=n; i++) rank[p][sa[p][i]]=rank[p][sa[p][i-1]]+(a[sa[p][i]]!=a[sa[p][i-1]]);
     for (int k=1; k<n; k<<=1,swap(p,q)) cal_sa(sa[p],rank[p],sa[q],rank[q],k);
     get_height();
 }
 bool check(int L)
 {
     int cnt=0;
     memset(vis,0,sizeof(vis));
     for (int i=2; i<=n; i++)
     {
         if (height[i]<L)
         {
             cnt=0;
             memset(vis,0,sizeof(vis));
             continue;
         }
         if (!vis[id[sa[p][i-1]]]) vis[id[sa[p][i-1]]]=1,cnt++;
         if (!vis[id[sa[p][i]]]) vis[id[sa[p][i]]]=1,cnt++;
         if (cnt==len)
         {
             for (int j=0; j<L; j++)
                 ans[j]=a[sa[p][i]+j];
             return 1;
         }
     }
     return 0;
 }
 int main(int argc, char const *argv[])
 {
     while (scanf("%d",&n) && n)
     {
         len=0;
         memset(v,0,sizeof(v));
         for (int i=1; i<=n; i++)
         {
             char ch[205];
             scanf("%s",ch+1);
             for (int j=1; j<=strlen(ch+1); j++) a[++len]=ch[j],id[len]=i;
             a[++len]=150+i; id[len]=i;
         }
         swap(n,len);
         work();
     //    for (int i=1; i<=n; i++) cout<<height[i]<<"  "<<id[sa[p][i]]<<endl;
         int l=1,r=205; bool flag=0;
         while (l<=r)
         {
             int mid=l+r>>1;
             if (check(mid)) flag=1,l=mid+1;
                 else r=mid-1;
         }
         if (flag) printf("%s\n",ans);
             else puts("IDENTITY LOST");
     }
     return 0;
 }*/

 #include<cstdio>
 #include<iostream>
 #include<cstring>
 #include<algorithm>
 using namespace std;
 #define maxn 888888
 int t1[maxn],t2[maxn],c[maxn],sa[maxn],rank[maxn],height[maxn];
 bool cmp(int *r, int a, int b, int l)
 {
     return r[a]==r[b] && r[a+l]==r[b+l];
 }
 void da(int str[], int n, int m)
 {
     n++; int *x=t1,*y=t2;
     for (int i=; i<m; i++) c[i]=;
     for (int i=; i<n; i++) c[x[i]=str[i]]++;
     for (int i=; i<m; i++) c[i]+=c[i-];
     for (int i=n-; i>=; i--) sa[--c[x[i]]]=i;
     for (int j=; j<=n; j<<=)
     {
         int p=;
         for (int i=n-j; i<n; i++) y[p++]=i;
         for (int i=; i<n; i++) if (sa[i]>=j) y[p++]=sa[i]-j;
         for (int i=; i<m; i++) c[i]=;
         for (int i=; i<n; i++) c[x[y[i]]]++;
         for (int i=; i<m; i++) c[i]+=c[i-];
         for (int i=n-; i>=; i--) sa[--c[x[y[i]]]]=y[i];
         swap(x,y);
         p=; x[sa[]]=;
         for (int i=; i<n; i++) x[sa[i]]=cmp(y,sa[i-],sa[i],j)?p-:p++;
         if (p>=n) break;
         m=p;
     }
     int k=; n--;
     for (int i=; i<=n; i++) rank[sa[i]]=i;
     for (int i=; i<n; i++)
     {
         if (k) k--;
         int j=sa[rank[i]-];
         while (str[i+k]==str[j+k]) k++;
         height[rank[i]]=k;
     }
 }
 int n,res,a[maxn],id[maxn],vis[];
 char s[],ans[];
 int check(int k)
 {
     int cnt=;
     memset(vis,,sizeof(vis));
     for(int i=;i<=res;i++)
     {
         if(height[i]<k)
         {
             memset(vis,,sizeof(vis));
             cnt=;
             continue;
         }
         if(!vis[id[sa[i-]]])
             vis[id[sa[i-]]]=,cnt++;
         if(!vis[id[sa[i]]])
             vis[id[sa[i]]]=,cnt++;
         if(cnt==n)
         {
             for(int j=;j<k;j++)
                 ans[j]=a[sa[i]+j];
             ans[k]='\0';
             return ;
         }
     }
     return ;
 }
 int main()
 {
     while(~scanf("%d",&n),n)
     {
         res=;
         for(int i=;i<n;i++)
         {
             scanf("%s",s);
             int len=strlen(s);
             for(int j=;j<len;j++)
                 a[res]=s[j],id[res++]=i;
             a[res]='#'+i;
             id[res++]='#'+i;
         }
         a[res]=;
         da(a,res,);
         int l=,r=strlen(s),flag=;
         while(l<=r)
         {
             int mid=(l+r)>>;
             if(check(mid))
             {
                 flag=;
                 l=mid+;
             }
             else r=mid-;
         }
         if(flag)printf("%s\n",ans);
         else printf("IDENTITY LOST\n");
     }
     return ;
 }