【后缀数组】板子 from Kausal
作者：互联网
O(nlogn)
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N=100010;
int wa[N],wb[N],wv[N],wss[N],rak[N],height[N],cal[N],n,sa[N];
char s[N];
int cmp(int *r,int a,int b,int l)
{return r[a]==r[b]&&r[a+l]==r[b+l];}
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++) wss[i]=0;
for(i=0;i<n;i++) wss[x[i]=r[i]]++;
for(i=1;i<M;i++) wss[i]+=wss[i-1];
for(i=n-1;i>=0;i--) sa[--wss[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++) wss[i]=0;
for(i=0;i<n;i++) wss[wv[i]]++;
for(i=1;i<M;i++) wss[i]+=wss[i-1];
for(i=n-1;i>=0;i--) sa[--wss[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=1;i<=n;i++) rak[sa[i]]=i;
for(i=0;i<n;height[rak[i++]]=k)
for(k?k--:0,j=sa[rak[i]-1];r[i+k]==r[j+k];k++);
for(int i=n;i;i--)rak[i]=rak[i-1],sa[i]++;
}
int main(){
int cas=1;
while(~scanf("%s",s+1)){
n=strlen(s+1);
for(int i=1;i<=n;i++)
cal[i]=s[i];
cal[n+1]=0;
da(cal+1,sa,n+1,200);
calheight(cal+1,sa,n);
for(int i=1;i<=n;i++) {
printf("%d ",height[i]);
}puts("");
for(int i=1;i<=n;i++) {
printf("%d ",sa[i]);
}puts("");
for(int i=1;i<=n;i++) {
printf("%d ",rak[i]);
}puts("");
}
}
O(n)
#include <cstdio>
#include <cstring>
#include <algorithm>
#define F(x) ((x) / 3 + ((x) % 3 == 1 ? 0 : tb))
#define G(x) ((x) < tb ? (x) * 3 + 1 : ((x) - tb) * 3 + 2)
using namespace std;
const int N = 3*(1e5+5);
int wa[N], wb[N], ws[N], wv[N], sa[N];
int rak[N], height[N], cal[N],n;
char s[N],ans[N],s1[N];
int cnt[N];
int c0(int *r, int a, int b) {
return r[a] == r[b] && r[a + 1] == r[b + 1] && r[a + 2] == r[b + 2];
}
int c12(int k, int *r, int a, int b) {
if (k == 2)
return r[a] < r[b] || r[a] == r[b] && c12(1, r, a + 1, b + 1);
return r[a] < r[b] || r[a] == r[b] && wv[a + 1] < wv[b + 1];
}
void Rsort(int *r, int *a, int *b, int n, int m) {
for (int i = 0; i < n; i++) wv[i] = r[a[i]];
for (int i = 0; i < m; i++) ws[i] = 0;
for (int i = 0; i < n; i++) ws[wv[i]]++;
for (int i = 1; i < m; i++) ws[i] += ws[i - 1];
for (int i = n - 1; i >= 0; i--) b[--ws[wv[i]]] = a[i];
}
void dc3(int *r, int *sa, int n, int m) {
int i, j, *rn = r + n, *san = sa + n, ta = 0, tb = (n + 1) / 3, tbc = 0, p;
r[n] = r[n + 1] = 0;
for (i = 0; i < n; i++) if (i % 3 != 0) wa[tbc++] = i;
Rsort(r + 2, wa, wb, tbc, m);
Rsort(r + 1, wb, wa, tbc, m);
Rsort(r, wa, wb, tbc, m);
for (p = 1, rn[F(wb[0])] = 0, i = 1; i < tbc; i++)
rn[F(wb[i])] = c0(r, wb[i - 1], wb[i]) ? p - 1 : p++;
if (p < tbc) dc3(rn, san, tbc, p);
else for (i = 0; i < tbc; i++) san[rn[i]] = i;
for (i = 0; i < tbc; i++) if (san[i] < tb) wb[ta++] = san[i] * 3;
if (n % 3 == 1) wb[ta++] = n - 1;
Rsort(r, wb, wa, ta, m);
for (i = 0; i < tbc; i++) wv[wb[i] = G(san[i])] = i;
for (i = 0, j = 0, p = 0; i < ta && j < tbc; p++)
sa[p] = c12(wb[j] % 3, r, wa[i], wb[j]) ? wa[i++] : wb[j++];
for (; i < ta; p++) sa[p] = wa[i++];
for (; j < tbc; p++) sa[p] = wb[j++];
//for(int i=n;i;i--) rak[i]=rak[i-1];
//for(int i=n;i;i--) sa[i]++;
}
void calheight(int *r, int *sa, int n) {
int i, j, k = 0;
for (i = 1; i <= n; i++) rak[sa[i]] = i;
for (i = 0; i < n; height[rak[i++]] = k)
for (k ? k-- : 0, j = sa[rak[i] - 1]; r[i + k] == r[j + k]; k++);
for(int i=n;i;i--) rak[i]=rak[i-1];
for(int i=n;i;i--) sa[i]++;
}
int main() {
while (scanf("%s", s+1)&&s[1] != '#') {
n = strlen(s+1);
for (int i = 1; i <= n; i++)
cal[i] = s[i] - 'a' + 1;
cal[n+1] = 0;
dc3(cal+1, sa, n + 1, 30);
calheight(cal+1, sa, n);
for(int i=1;i<=n;i++) {
printf("%d ",height[i]);
}puts("");
}
return 0;
}
标签：wb,wa,后缀,++,板子,int,sa,tbc,Kausal 来源： https://www.cnblogs.com/Tecode/p/15079854.html