poj 3261 Milk Patterns(后缀数组）

#include<cstdio>
#include<cstring>
#include<vector>
#include<algorithm>
#define maxn 200100
using namespace std;
int r[maxn];
int Rank[maxn],sa[maxn],height[maxn];
int wa[maxn],wb[maxn],wv[maxn],ws[maxn];
char a[maxn],b[maxn];
int cmp(int *r,int a,int b,int le)
{
return r[a]==r[b]&&r[a+le]==r[b+le];
}
void da(int *r,int *sa,int n,int m)
{
int i,j,p,*x=wa,*y=wb,*t;
for ( i = 0; i < m; i++) ws[i]=0;
for ( i = 0; i < n; i++) ws[ x[i] = r[i] ]++;
for ( i = 1; i < m; i++) ws[i]+=ws[i-1];
for ( i = n-1; i >= 0; i--) sa[--ws[x[i]]]=i;
for ( j = 1,p=1; p <n ; j*=2,m=p)
{
for ( p = 0,i=n-j; i < n; i++) y[p++]=i;
for ( i = 0; i < n; i++) if(sa[i]>=j) y[p++]=sa[i]-j;
for ( i = 0; i < n; i++) wv[i]=x[y[i]];
for ( i = 0; i < m; i++) ws[i]=0;
for ( i = 0; i < n; i++) ws[wv[i]]++;
for ( i = 1; i < m; i++) ws[i]+=ws[i-1];
for ( i = n-1; i >= 0 ; i--) sa[--ws[wv[i]]]=y[i];
for (t=x,x=y,y=t,p=1,x[sa[0]]=0,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 i,j,k=0;
for ( i = 0; i <=n ; i++) Rank[sa[i]]=i;
for(i=0;i<n;height[Rank[i++]]=k)
for(k?k--:0,j=sa[Rank[i]-1];r[i+k]==r[j+k];k++);
return ;
}
struct pi
{
int min;
}pp[4*maxn];
int main()
{
int i,n,k,f,le,ri,mid,p;
while(scanf("%d%d",&n,&k)!=EOF)
{
for(i=0;i<n;i++)
{
scanf("%d",&f);
r[i]=f+1;
}
if(k>n)
{
printf("0\n");
continue;
}
if(k==1){
printf("%d\n",n);
continue;
}
r
=0;
da(r,sa,n+1,20002);
calheight(r,sa,n);
le=1;
ri=n;
while(le<=ri)
{
mid=(le+ri)/2;
f=0;
for(i=2;i<=n;i++){
if(height[i]>=mid){
p=i;
while(p<=n&&height[p]>=mid) p++;
if(p-i>=k-1){
f=1;
break;
}
i=p;
}
}
if(f){
le=mid+1;
}
else
ri=mid-1;
}
printf("%d\n",ri);
}
return 0;
}