bzoj 2251: [2010Beijing Wc]外星联络

黄学长说是模板题,,然而不会。。

大概是按后缀数组的顺序(也就是字典序)来枚举一下,然后再按长度枚举一下,各种各样的暴力,,,然用在height上搞2333,不会啊

 1 #include<bits/stdc++.h>
 2 #define N 100005<<2
 3 #define LL long long
 4 #define inf 0x3f3f3f3f
 5 using namespace std;
 6 inline int ra()
 7 {
 8     int x=0,f=1; char ch=getchar();
 9     while (ch<'0' || ch>'9') {if (ch=='-') f=-1; ch=getchar();}
10     while (ch>='0' && ch<='9') {x=x*10+ch-'0'; ch=getchar();}
11     return x*f;
12 }
13 char ch[N];
14 int n,k,p,q;
15 int a[N],rank[2][N],sa[2][N],h[N],v[N];
16 void cal_sa(int sa[N], int rank[N], int Sa[N], int Rank[N])
17 {
18     for (int i=1; i<=n; i++) v[rank[sa[i]]]=i;
19     for (int i=n; i>=1; i--)
20         if (sa[i]>k) Sa[v[rank[sa[i]-k]]--]=sa[i]-k;
21     for (int i=n-k+1; i<=n; i++) Sa[v[rank[i]]--]=i;
22     for (int i=1; i<=n; i++) Rank[Sa[i]]=Rank[Sa[i-1]]+(rank[Sa[i]]!=rank[Sa[i-1]] || rank[Sa[i]+k]!=rank[Sa[i-1]+k]);
23 }
24 void get_height()
25 {
26     k=0;
27     for (int i=1; i<=n; i++)
28     {
29         if (rank[p][i]==1) h[1]=0;
30         else{
31             int j=sa[p][rank[p][i]-1];
32             while (a[i+k]==a[j+k]) k++;
33             h[rank[p][i]]=k; 
34             if (k>0) k--;
35         }
36     }
37 }
38 void work()
39 {
40     p=0,q=1;
41     for (int i=1; i<=n; i++) v[a[i]]++;
42     for (int i=1; i<=30; i++) v[i]+=v[i-1];
43     for (int i=1; i<=n; i++) sa[p][v[a[i]]--]=i;
44     for (int i=1; i<=n; i++) rank[p][sa[p][i]]=rank[p][sa[p][i-1]]+(a[sa[p][i]]!=a[sa[p][i-1]]);
45     for (k=1; k<n; k<<=1,p^=1,q^=1) cal_sa(sa[p],rank[p],sa[q],rank[q]);
46     get_height();
47 }
48 int main()
49 {
50     n=ra(); scanf("%s",ch+1);
51     for (int i=1; i<=n; i++) a[i]=ch[i]-'0'+1;
52     work();
53     for (int i=1; i<=n; i++)
54         for (int j=h[i]+1; sa[p][i]+j-1<=n; j++)
55         {
56             int l=i,r;
57         //    for (l=i; l>=1 && h[l]>=j; l--);
58             for (r=i+1; r<=n && h[r]>=j; r++);
59             if (r-l>1) printf("%d\n",r-l);
60         }
61     return 0;
62 }

 

posted @ 2017-02-28 07:03  ws_ccd  阅读(122)  评论(0编辑  收藏  举报