ACM-ICPC 2018 焦作赛区网络预赛 H题 String and Times（SAM）

Now you have a string consists of uppercase letters, two integers AA and BB. We call a substring wonderful substring when the times it appears in that string is between AA and BB (A \le times \le BA≤times≤B). Can you calculate the number of wonderful substrings in that string?

Input

Input has multiple test cases.

For each line, there is a string SS, two integers AA and BB.

\sum length(S) \le 2 \times 10^6∑length(S)≤2×106,

1 \le A \le B \le length(S)1≤A≤B≤length(S)

Output

For each test case, print the number of the wonderful substrings in a line.

样例输入复制

AAA 2 3
ABAB 2 2

样例输出复制

2
3

题目来源

ACM-ICPC 2018 焦作赛区网络预赛

题解：SAM模板题

参考代码：

 //H  求子串出现次数在k1=<num<=k2;
 #include <bits/stdc++.h>
 using namespace std;
 const int MAXN = 4e5+;
 char ss[];
 const int LetterSize = ;

 int tot, last,ch[MAXN][LetterSize],fa[MAXN],len[MAXN];
 int sum[MAXN],tp[MAXN],cnt[MAXN]; 

 void init()
 {
     last = tot = ;
     len[] = ;
     memset(ch,,sizeof ch);
     memset(fa,,sizeof fa);
     memset(cnt,,sizeof cnt);
 }

 void add( int x)
 {
     int p = last, np = last = ++tot;
     len[np] = len[p] + , cnt[last] = ;
     while( p && !ch[p][x]) ch[p][x] = np, p = fa[p];
     if(p == ) fa[np] = ;
     else
     {
         int q = ch[p][x];
         if( len[q] == len[p] + )
             fa[np] = q;
         else
         {
             int nq = ++tot;
             memcpy( ch[nq], ch[q], sizeof ch[q]);
             len[nq] = len[p] + , fa[nq] = fa[q], fa[q] = fa[np] = nq;
             while( p && ch[p][x] == q)  ch[p][x] = nq, p = fa[p];
         }
     }
 }

 void toposort()
 {
     for(int i = ; i <= len[last]; i++)   sum[i] = ;
     for(int i = ; i <= tot; i++)   sum[len[i]]++;
     for(int i = ; i <= len[last]; i++)   sum[i] += sum[i-];
     for(int i = ; i <= tot; i++)   tp[sum[len[i]]--] = i;
 }

 int main()
 {

     int k1,k2;
     while(scanf("%s",ss)!=EOF)
     {
         init();
         scanf("%d%d",&k1,&k2);
         long long ans=;
         for(int i=,len=strlen(ss);i<len;i++) add(ss[i]-'A');
         toposort();
         for(int i=tot;i;i--)
         {
             int p=tp[i],fp=fa[p];
             cnt[fp]+=cnt[p];
             if(cnt[p]>=k1 && cnt[p]<=k2) ans+=len[p]-len[fp];
         }
         printf("%lld\n",ans);
     }

     return ;
 }