POJ 1226 Substrings(后缀数组)

int r
,sa
,wa
,wb
,wd
,rank
,h
;

int cmp(int *r,int a,int b,int len)
{
return r[a]==r[b]&&r[a+len]==r[b+len];
}

void da(int *r,int *sa,int n,int m)
{
int i,j,p,*x=wa,*y=wb,*t;
FOR0(i,m) wd[i]=0;
FOR0(i,n) wd[x[i]=r[i]]++;
FOR1(i,m-1) wd[i]+=wd[i-1];
FORL0(i,n-1) sa[--wd[x[i]]]=i;
for(j=1,p=1;p<n;j<<=1,m=p)
{
p=0;
FOR(i,n-j,n-1) y[p++]=i;
FOR0(i,n) if(sa[i]>=j) y[p++]=sa[i]-j;
FOR0(i,m) wd[i]=0;
FOR0(i,n) wd[x[i]]++;
FOR1(i,m-1) wd[i]+=wd[i-1];
FORL0(i,n-1) sa[--wd[x[y[i]]]]=y[i];
t=x;x=y;y=t;p=1;x[sa[0]]=0;
FOR1(i,n-1) x[sa[i]]=cmp(y,sa[i-1],sa[i],j)?p-1:p++;
}
}

void calHeight(int *r,int *sa,int n)
{
int i,j,k=0;
FOR1(i,n) rank[sa[i]]=i;
FOR0(i,n)
{
if(k) k--;
j=sa[rank[i]-1];
while(i+k<n&&j+k<n&&r[i+k]==r[j+k]) k++;
h[rank[i]]=k;
}
}

int n,m,b
;
char s
;

int OK(int x)
{
int i,j,k,t,L,R,hash[105];
FOR1(i,m)
{
L=i;
while(L<=m&&h[L]<x) L++;
if(L>m) break;
R=L;
while(R<=m&&h[R]>=x) R++;
clr(hash,0);
FOR(j,L-1,R-1) if(b[sa[j]]!=-1)
{
hash[b[sa[j]]]=1;
}
FOR1(j,n) if(!hash[j]) break;
if(j>n) return 1;
i=R;
}
return 0;
}

void deal()
{
int low=0,high=100,mid;
while(low<=high)
{
mid=(low+high)>>1;
if(OK(mid)) low=mid+1;
else high=mid-1;
}
if(low<=100&&OK(low)) PR(low);
else if(high>=0&&OK(high)) PR(high);
}

int main()
{
int C;
RD(C);
while(C--)
{
RD(n);
int i,j,L=0,len,Max=130;
FOR1(i,n)
{
RD(s); len=strlen(s);
FOR0(j,len) r[L++]=s[j],b[L-1]=i;
r[L++]=Max++;
b[L-1]=-1;
FORL0(j,len-1) r[L++]=s[j],b[L-1]=i;
r[L++]=Max++;
b[L-1]=-1;
}
r[L]=0;
da(r,sa,L+1,Max);
calHeight(r,sa,L);
m=L;
deal();
}
return 0;
}