后缀数组模板

花了点时间搞定了下后缀数组，UOJ的例题，getSA有点厉害需要多思考下才行
算法合集——后缀数组

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<cstdlib>
#include<algorithm>
#define LL long long
#define fo(i,a,b) for(int i=a;i<=b;i++)
#define down(i,a,b) for(int i=a;i>=b;i--)
using namespace std;
inline LL read()
{
LL d=0,f=1;char s=getchar();
while(s<'0'||s>'9'){if(s=='-')f=-1;s=getchar();}
while(s>='0'&&s<='9'){d=d*10+s-'0';s=getchar();}
return d*f;
}
#define N 100005
char s
;
int a
,rank
,height
;
int n;

bool com(int a,int b)
{
int i=a,j=b;
while(s[i]==s[j])
{
i++;j++;
if(j>n)return 0;
if(i>n)return 1;
}
if(s[i]<s[j])return 1;
else return 0;
}

void getheight()
{
int i,j,k=0;
for(i=1;i<=n;height[rank[i++]]=k)
for(k?k--:0,j=a[rank[i]-1];s[i+k]==s[j+k];k++)
{
// cout<<s[i+k]<<s[j+k]<<' '<<j<<' '<<k<<' '<<n<<endl;
// cout<<i<<' '<<rank[i]<<' '<<a[rank[i-1]]<<endl;
// if(i+k>n&&j+k>n)break;
}
fo(i,2,n)printf("%d ",height[i]);printf("\n");
}

void getsa()
{
fo(i,1,n)a[i]=i;
sort(a+1,a+n+1,com);
fo(i,1,n)rank[a[i]]=i;
fo(i,1,n)printf("%d ",a[i]);printf("\n");
}

void getsaGG()
{
int c
;int m=26;
fo(i,1,m)c[i]=0;
fo(i,1,n)rank[i]=s[i]-96,c[rank[i]]++;
fo(i,1,m)c[i]+=c[i-1];
down(i,n,1)a[c[rank[i]]--]=i;
for(int k=1;k<=n;k<<=1)
{
int p=0;
fo(i,n-k+1,n)height[++p]=i;
fo(i,1,n)if(a[i]>k)height[++p]=a[i]-k;
fo(i,1,m)c[i]=0;
fo(i,1,n)c[rank[height[i]]]++;
fo(i,1,m)c[i]+=c[i-1];
down(i,n,1)a[c[rank[height[i]]]--]=height[i];
swap(rank,height);p=0;rank[a[1]]=++p;
fo(i,2,n)
if(height[a[i]]==height[a[i-1]]&&height[a[i]+k]==height[a[i-1]+k])
rank[a[i]]=p;else rank[a[i]]=++p;
if(p==n)break;
m=p;
}
fo(i,1,n)printf("%d ",a[i]);printf("\n");
}

int main()
{
scanf("%s",s+1);
n=strlen(s+1);
getsaGG();
getheight();
// build_height();
return 0;
}