bzoj 3238: [Ahoi2013]差异

// MADE BY QT666
#include<cstdio>
#include<algorithm>
#include<cmath>
#include<iostream>
#include<cstring>
using namespace std;
typedef long long ll;
const int N=600050;
int gi(){
  int x=0,flag=1;
  char ch=getchar();
  while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘) flag=-1;ch=getchar();}
  while(ch>=‘0‘&&ch<=‘9‘) x=x*10+ch-‘0‘,ch=getchar();
  return x*flag;
}
int sa[N],len,y[N],rk,rnk[N],height[N],fa[N];
char a[N];
ll ansz[N],ansl[N],Ans,sz[N],le[N];
struct data{
  int fir,sec,id;
}x[N];
bool cmp(const data &a,const data &b){
  if(a.fir==b.fir) return a.sec<b.sec;
  else return a.fir<b.fir;
}
void work2(){
  rk=1;y[x[1].id]=rk;
  for(int i=2;i<=len;i++){
    if(x[i-1].fir!=x[i].fir||x[i-1].sec!=x[i].sec) rk++;
    y[x[i].id]=rk;
  }
}
void work(){
  sort(x+1,x+1+len,cmp);work2();
  for(int i=1;i<=len;i<<=1){
    for(int j=1;j+i<=len;j++) x[j].fir=y[j],x[j].sec=y[j+i],x[j].id=j;
    for(int j=len-i+1;j<=len;j++) x[j].fir=y[j],x[j].sec=0,x[j].id=j;
    sort(x+1,x+1+len,cmp);work2();
    if(rk==len) break;
  }
}
void get_height(){
  int kk=0;for(int i=1;i<=len;i++) rnk[sa[i]]=i;
  for(int i=1;i<=len;i++){
    if(kk) kk--;
    int j=sa[rnk[i]-1];
    while(a[i+kk]==a[j+kk]) kk++;
    height[rnk[i]]=kk;
  }
}
struct Data{
  int l,r,hi;
}g[N];
bool cmp2(const Data &a,const Data &b){
  return a.hi>b.hi;
}
int find(int x) {
  if(x!=fa[x]) fa[x]=find(fa[x]);
  return fa[x];
}
void merge(int x,int y,int hi){
  ansz[hi]+=sz[x]*sz[y];
  ansl[hi]+=le[x]*sz[y]+le[y]*sz[x];
  fa[x]=y;sz[y]+=sz[x];le[y]+=le[x];
}
int main(){
  scanf("%s",a+1);len=strlen(a+1);
  for(int i=1;i<=len;i++) x[i].id=i,x[i].fir=x[i].sec=a[i]-‘a‘+1;
  work();for(int i=1;i<=len;i++) sa[y[i]]=i;
  for(int i=1;i<=len;i++) sz[i]=1,fa[i]=i,le[i]=len-i+1;
  get_height();for(int i=2;i<=len;i++) g[i-1]=(Data){sa[i-1],sa[i],height[i]};
  sort(g+1,g+len,cmp2);
  for(int i=1;i<=len;i++){
    int x=find(g[i].l),y=find(g[i].r);
    if(x!=y) merge(x,y,g[i].hi);
  }
  for(int i=0;i<=len;i++) Ans+=ansl[i]-2*ansz[i]*i;
  printf("%lld\n",Ans);
  return 0;
}