这是一道板子题,考的是一个状态中不同子串数量为len[i] - len[fa[i]],即集合中最长的后缀减去最短的后缀。
不过这题我遇到的问题在于字符集过于庞大,最后是通过用map去代替ch数组解决。
//
// Created by acer on 2021/2/16.
//
//判断子串,不同子串个数,所有子串字典序第i大,最长公共子串
#include "bits/stdc++.h"
#define int long long
using namespace std;
const int MAXN = 1e5 + 10;
int len[MAXN << 1];
map<int,int> ch[MAXN<<1];
int fa[MAXN << 1];
int last = 1;
int tot = 1;
int p;
int add(int c) {
p = last;
last = ++tot;
int np = last;
len[np] = len[p] + 1;
for (; p && !(ch[p][c]); p = fa[p]) ch[p][c] = np;
if (!p) fa[np] = 1;
else {
int q = ch[p][c];
if (len[q] == len[p] + 1) fa[np] = q;
else {
int nq = ++tot;
// memcpy(ch[nq],ch[q],sizeof(ch[nq]));
ch[nq] = ch[q];
fa[nq] = fa[q];
len[nq] = len[p] + 1;
fa[np] = fa[q] = nq;
for (; p && ch[p][c] == q; p = fa[p]) {
ch[p][c] = nq;
}
}
}
return len[last] - len[fa[last]];
}
map<int,int> mp;
int main() {
int n;cin >> n;
int res = 0;
int id = 0;
for (int i = 1; i <= n; ++i) {
int s;cin >> s;
if (!mp[s]) mp[s] = ++id;
res += add(mp[s]);
cout << res << endl;
}
}