1 #include <bits/stdc++.h>
2 using namespace std;
3 typedef long long ll;
4 const int maxn = 1e6+5;
5 char s[maxn];
6 int n;
7 int record[maxn]; // 记录i结点在原字符串的位置
8 int sum[maxn*4];
9 void pushup(int rt) {
10 sum[rt] |= sum[rt*2];
11 sum[rt] |= sum[rt*2+1];
12 }
13 void build(int l, int r, int rt) {
14 if (l == r) {
15 sum[rt] |= 1<<(s[l]-'a');
16 return;
17 }
18 int mid = (l+r)/2;
19 build(l,mid,rt*2);
20 build(mid+1,r,rt*2+1);
21 pushup(rt);
22 }
23 int query(int be, int ed, int l, int r, int rt) {
24 if (be <= l && r <= ed) {
25 return sum[rt];
26 }
27 int mid = (l+r)/2, res = 0;
28 if (be <= mid) res |= query(be,ed,l,mid,rt*2);
29 if (ed > mid) res |= query(be,ed,mid+1,r,rt*2+1);
30 return res;
31 }
32
33 struct PAM {
34 int last;
35 struct Node {
36 ll cnt, len, fail, son[27]; // cnt为以i为结尾的回文子串个数，len为长度
37 Node(int len, int fail) : len(len), fail(fail), cnt(0){
38 memset(son, 0, sizeof(son));
39 };
40 };
41 vector<Node> st;
42 inline int newnode(int len, int fail = 0) {
43 st.emplace_back(len, fail);
44 return st.size()-1;
45 }
46 inline int getfail(int x, int n) {
47 while (s[n-st[x].len-1] != s[n]) x = st[x].fail;
48 return x;
49 }
50 inline void extend(int c, int i) {
51 int cur = getfail(last, i);
52 if (!st[cur].son[c]) {
53 int nw = newnode(st[cur].len+2, st[getfail(st[cur].fail, i)].son[c]);
54 st[cur].son[c] = nw;
55 }
56 st[ last=st[cur].son[c] ].cnt++;
57 record[last] = i;
58 }
59 void init() {
60 scanf("%s", s+1);
61 n = strlen(s+1);
62 s[0] = 0;
63 newnode(0, 1), newnode(-1);
64 last = 0;
65 for (int i = 1; i <= n; i++)
66 extend(s[i]-'a', i);
67 }
68 ll count() {
69 for (int i = st.size()-1; i >= 0; i--)
70 st[st[i].fail].cnt += st[i].cnt;
71
72 ll ans = n;
73 for (int i = 2; i <= st.size()-1; i++) {
74 if (st[i].len <= 1) continue;
75
76 int L = record[i]-st[i].len+1, R = record[i];
77 int res = query(L,R,1,n,1);
78 int num = 0;
79 while (res) {
80 if (res&1) num++;
81 res >>= 1;
82 }
83 ans += st[i].cnt*num;
84 }
85 return ans;
86 }
87 }pam;
88 int main() {
89 pam.init();
90 build(1,n,1);
91 printf("%lld\n",pam.count());
92 return 0;
93 }
