[Bzoj]1031: [JSOI2007]字符加密Cipher

 1 #include<iostream>
 2 #include<cstring>
 3 using namespace std;
 4 
 5 const int MAXN=300000;
 6 int WA[MAXN],WB[MAXN],WV[MAXN],WS[MAXN];
 7 int Rank[MAXN],Height[MAXN];
 8  
 9 int cmp(int *r , int a, int b, int l)
10 {
11     return r[a] == r[b] && r[a+l] == r[b+l];
12 }
13 void DA(char *r , int *sa , int n, int m)
14 {
15     int i, j, p, *x = WA, *y = WB;
16     for(i = 0; i < m; i++)  WS[i] = 0;
17     for(i = 0; i < n; i++) WS[x[i] = r[i]]++;
18     for(i = 1; i < m; i++) WS[i] += WS[i-1];
19     for(i = n-1; i >= 0; i--) sa[--WS[x[i]]] = i;
20 
21     for(j = 1,p = 1; p < n ; j <<= 1,m = p)
22     {
23         for(p = 0, i = n - j; i < n; i++) y[p++]=i;
24         for(i = 0; i < n; i++)
25             if(sa[i] >= j)
26                 y[p++] = sa[i] - j;
27         for(i = 0; i < n; i++) WV[i] = x[y[i]];
28         for(i = 0; i < m; i++) WS[i] = 0;
29         for(i = 0; i < n; i++) WS[WV[i]]++;
30         for(i = 1; i < m; i++) WS[i] += WS[i-1];
31         for(i = n-1; i >= 0; i--) sa[--WS[WV[i]]] = y[i];
32         for(swap(x,y),p = 1,x[sa[0]] = 0,i = 1; i < n;i++)
33             x[sa[i]]=cmp(y,sa[i-1],sa[i],j)?p-1:p++;
34     }
35 }
36 
37 void calheight(char *r,int *sa,int n)
38 {
39     int i,j,k=0;
40     for(i=1;i<=n;i++)Rank[sa[i]]=i;
41     for(i=0;i<n;Height[Rank[i++]]=k)
42         for(k?k--:0,j=sa[Rank[i]-1];r[i+k]==r[j+k];k++);
43     return;
44 }
45 
46 char str[MAXN];
47 int sa[MAXN];
48 
49 int main()
50 {
51     cin>>(str+1);
52     int n=strlen(str+1);
53     for(int i=1;i<=n;i++) str[i+n]=str[i];
54     str[0]=0;
55     DA(str,sa,2*n+1,256);
56     //calheight(str,sa,n);
57     for(int i=1;i<=2*n;i++)
58         if(sa[i]<=n)
59             cout<<str[sa[i]+n-1];
60     return 0;
61 }