HDU 4552 怪盗基德的挑战书

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 const int maxn = 100010;
 4 char s[maxn];
 5 int sa[maxn],rk[maxn],height[maxn],n;
 6 int c[maxn],tmp[2][maxn];
 7 void build_sa(int m) {
 8     int i,*x = tmp[0],*y = tmp[1];
 9     for(i = 0; i < m; ++i) c[i] = 0;
10     for(i = 0; i < n; ++i) c[x[i] = s[i]]++;
11     for(i = 1; i < m; ++i) c[i] += c[i-1];
12     for(i = n-1; i >= 0; --i) sa[--c[x[i]]] = i;
13 
14     for(int k = 1; k <= n; k <<= 1) {
15         int p = 0;
16         for(i = 0; i < m; ++i) c[i] = 0;
17         for(i = n - k; i < n; ++i) y[p++] = i;
18         for(i = 0; i < n; ++i) if(sa[i] >= k) y[p++] = sa[i]-k;
19         for(i = 0; i < n; ++i) c[x[y[i]]]++;
20         for(i = 1; i < m; ++i) c[i] += c[i-1];
21         for(i = n - 1; i >= 0; --i) sa[--c[x[y[i]]]] = y[i];
22         swap(x,y);
23         x[sa[0]] = 0;
24         for(p = i = 1; i < n; ++i)
25             if(y[sa[i]] == y[sa[i-1]] && y[sa[i]+k] == y[sa[i-1]+k])
26                 x[sa[i]] = p-1;
27             else x[sa[i]] = p++;
28         if((m = p) >= n) break;
29     }
30 }
31 void getHeight() {
32     int i,j,k = 0;
33     for(i = 0; i < n; ++i) rk[sa[i]] = i;
34     for(i = 0; i < n; ++i) {
35         if(k) --k;
36         j = sa[rk[i]-1];
37         while(i + k < n && j + k < n && s[i+k] == s[j+k]) ++k;
38         height[rk[i]] = k;
39     }
40 }
41 int main() {
42     while(~scanf("%s",s)) {
43         n = strlen(s) + 1;
44         build_sa(128);
45         getHeight();
46         int pos = rk[0],tmp = n-1,ret = n-1;
47         while(pos + 1 < n && tmp) {
48             tmp = min(tmp,height[++pos]);
49             ret += tmp;
50         }
51         pos = rk[0],tmp = n-1;
52         while(pos > 1 && tmp) {
53             tmp = min(tmp,height[pos--]);
54             ret += tmp;
55         }
56         printf("%d\n",ret%256);
57     }
58     return 0;
59 }