题目链接 ： https://www.acwing.com/problem/content/description/142/
Hash + 二分
#include <bits/stdc++.h>
using namespace std;
const int maxn = 3e5 + 7;
typedef unsigned long long ull;
const ull mod = 131;
ull p[maxn],h[maxn];
int sa[maxn],rank[maxn],height[maxn];
char str[maxn];
int n ;
ull get(int x,int y){
return h[y] - h[x - 1] * p[y - x + 1];
}
int lcp(int x,int y){
int l = 0 ,r = min(n - x + 1,n - y + 1);
while(l < r){
int mid = (l + r + 1) >> 1;
if(get(x,x + mid - 1) != get(y,y + mid - 1)) r = mid - 1;
else l = mid;
}
return l;
}
bool cmp(int x , int y){
int l = lcp(x,y);
int av = x + l > n ? INT_MIN : str[x + l];
int bv = y + l > n ? INT_MIN : str[y + l];
return str[x + l] < str[y + l];
}
int main(){
scanf("%s",str + 1);
n = strlen(str + 1);
p[0] = 1;
for(int i = 1;i <= n ;i ++){
p[i] = mod * p[i-1];
h[i] = mod * h[i-1] + str[i] - '0' + 1;
sa[i] = i;
}
sort(sa + 1, sa + 1 + n , cmp);
for(int i = 2;i <= n ;i ++){
height[i] = lcp(sa[i],sa[i-1]);
}
for(int i = 1;i <= n ;i ++) printf("%d%c",sa[i]-1," \n"[i==n]);
printf("0 ");
for(int i = 2;i <= n ;i ++) printf("%d%c",height[i]," \n"[i==n]);
return 0;
}
后缀数组
#include <bits/stdc++.h>
using namespace std;
const int maxn = 3e5 + 7;
struct DA{
bool cmp(int *r,int a,int b,int l){
return r[a]==r[b]&&r[a+l]==r[b+l];
}
int t1[maxn],t2[maxn],c[maxn];
int rank[maxn],height[maxn],RMQ[maxn],mm[maxn];
int best[20][maxn];
int r[maxn];
int sa[maxn];
int str[maxn];
void da(int n,int m){
n++;
int i,j,p,*x=t1,*y=t2;
for(i=0;i<m;i++)c[i]=0;
for(i=0;i<n;i++)c[x[i]=str[i]]++;
for(i=1;i<m;i++)c[i]+=c[i-1];
for(i=n-1;i>=0;i--)sa[--c[x[i]]]=i;
for(j=1;j<=n;j<<=1){
p=0;
for(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<m;i++)c[i]=0;
for(i=0;i<n;i++)c[x[y[i]]]++;
for(i=1;i<m;i++)c[i]+=c[i-1];
for(i=n-1;i>=0;i--)sa[--c[x[y[i]]]]=y[i];
swap(x,y);
p=1;x[sa[0]]=0;
for(i=1;i<n;i++)
x[sa[i]]=cmp(y,sa[i-1],sa[i],j)?p-1:p++;
if(p>=n)break;
m=p;
}
int k=0;
n--;
for(i=0;i<=n;i++)rank[sa[i]]=i;
for(i=0;i<n;i++){
if(k)k--;
j=sa[rank[i]-1];
while(str[i+k]==str[j+k])k++;
height[rank[i]]=k;
}
}
void initRMQ(int n){
for(int i=1;i<=n;i++)RMQ[i]=height[i];
mm[0]=-1;
for(int i=1;i<=n;i++)
mm[i]=((i&(i-1))==0)?mm[i-1]+1:mm[i-1];
for(int i=1;i<=n;i++)best[0][i]=i;
for(int i=1;i<=mm[n];i++)
for(int j=1;j+(1<<i)-1<=n;j++){
int a=best[i-1][j];
int b=best[i-1][j+(1<<(i-1))];
if(RMQ[a]<RMQ[b])best[i][j]=a;
else best[i][j]=b;
}
}
int askRMQ(int a,int b){
int t;
t=mm[b-a+1];
b-=(1<<t)-1;
a=best[t][a];b=best[t][b];
return RMQ[a]<RMQ[b]?a:b;
}
int lcp(int a,int b){
a=rank[a];b=rank[b];
if(a>b)swap(a,b);
return height[askRMQ(a+1,b)];
}
void print(int n){
// cout<<"sa[] ";
for(int i=2;i<=n;i++)cout<<sa[i]<<" ";cout<<endl;
// cout<<"rank[] ";
// for(int i=2;i<=n;i++)cout<<rank[i]<<" ";cout<<endl;
//cout<<"height[] ";
for(int i=2;i<=n;i++)cout<<height[i]<<" ";cout<<endl;
}
}AA,BB;
//n=8;
//* num[] = { 1, 1, 2, 1, 1, 1, 1, 2, $ }; 注意 num 最后一位为 0，其他 大于 0
//*rank[] = 4, 6, 8, 1, 2, 3, 5, 7, 0 ;rank[0 n-1] 为有效值，rank[n] 必定为 0 无效值
// *sa[] = 8, 3, 4, 5, 0, 6, 1, 7, 2 ;sa[1 n] 为有效值，sa[0] 必定为 n 是 无效值
//*height[]= 0, 0, 3, 2, 3, 1, 2, 0, 1 ;height[2 n] 为有效值
int main(int argc, char const *argv[])
{
string str;
cin >> str;
for(int i = 0;i < str.size();i ++) AA.str[i] = str[i] - '0' + 100;
AA.str[str.size()] = 0;
AA.da(str.size() + 1,600);
AA.print(str.size() + 1);
return 0;
}