C - Distinct Substrings （模板）

Posted 2021-01-11 ouyang_wsgwz

https://vjudge.net/problem/SPOJ-DISUBSTR

有两种方式来求去除重读的子串

 1 #include <bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 const int maxn = 50005;
 5 
 6 int t1[maxn],t2[maxn],c[maxn];
 7 bool cmp(int *r,int a,int b,int l)  {
 8     return r[a]==r[b] &&r[l+a] == r[l+b];
 9 }
10 
11 void get_sa(int str[],int sa[],int Rank[],int height[],int n,int m)
12 {
13     n++;
14     int p,*x=t1,*y=t2;
15     for(int i = 0; i < m; i++) c[i] = 0;
16     for(int i = 0; i < n; i++) c[x[i] = str[i]]++;
17     for(int i = 1; i < m; i++) c[i] += c[i-1];
18     for(int i = n-1; i>=0; i--) sa[--c[x[i]]] = i;
19     for(int j = 1; j <= n; j <<= 1)  {
20         p = 0;
21         for(int i = n-j; i < n; i++) y[p++] = i;
22         for(int i = 0; i < n; i++) if(sa[i] >= j) y[p++] = sa[i]-j;
23         for(int i = 0; i < m; i++) c[i] = 0;
24         for(int i = 0; i < n; i++) c[x[y[i]]]++ ;
25         for(int i = 1; i < m; i++) c[i] += c[i-1];
26         for(int i = n-1; i >= 0; i--)  sa[--c[x[y[i]]]] = y[i];
27         swap(x,y);
28         p = 1;
29         x[sa[0]] = 0;
30         for(int i = 1; i < n; i++)
31             x[sa[i]] = cmp(y,sa[i-1],sa[i],j)? p-1:p++;
32         if(p >= n) break;
33         m = p;
34     }
35     int k = 0;
36     n--;
37     for(int i = 0; i <= n; i++)
38         Rank[sa[i]] = i;
39     for(int i = 0; i < n; i++)  {
40         if(k) k--;
41         int j = sa[Rank[i]-1];
42         while(str[i+k] == str[j+k]) k++;
43         height[Rank[i]] = k;
44     }
45 }
46 
47 int Rank[maxn],height[maxn];
48 int sa[maxn];
49 char str[maxn];
50 int a[maxn];
51 int n;
52 
53 int main()
54 {
55     int T;
56     scanf("%d",&T);
57     while(T--)
58     {
59         int tot = 0;
60         scanf("%s",str);
61         int len = strlen(str);
62         for(int i = 0;i < len; i++)
63             a[i] = str[i];
64         a[len] = 0;
65         get_sa(a,sa,Rank,height,len,200);
66         long long res = 0;
67         long long ans = (len+1)*len/2;
68         for(int i=1;i<=len;i++){
69             res+=len-sa[i]-height[i];
70             ans-=height[i];
71         }
72         //printf("%lld
",res);
73         printf("%lld
", ans);
74     }
75     return 0;
76 }