【CodeForces123D】String

#include<bits/stdc++.h>
using namespace std;
const int MAXN = 100005;
template <typename T> void chkmax(T &x, T y) {x = max(x, y); }
template <typename T> void chkmin(T &x, T y) {x = min(x, y); }
template <typename T> void read(T &x) {
x = 0; int f = 1;
char c = getchar();
for (; !isdigit(c); c = getchar()) if (c == '-') f = -f;
for (; isdigit(c); c = getchar()) x = x * 10 + c - '0';
x *= f;
}
template <typename T> void write(T x) {
if (x < 0) x = -x, putchar('-');
if (x > 9) write(x / 10);
putchar(x % 10 + '0');
}
template <typename T> void writeln(T x) {
write(x);
puts("");
}
namespace SuffixAutomaton {
const int MAXN = 2 * 100005;
const int MAXC = 26;
int root, size, last;
int child[MAXN][MAXC];
int fail[MAXN], depth[MAXN], cnt[MAXN];
vector <int> a[MAXN];
long long ans;
int newnode(int dep) {
fail[size] = 0;
depth[size] = dep;
memset(child[size], 0, sizeof(child[size]));
return size++;
}
void extend(int ch) {
int p = last, np = newnode(depth[last] + 1);
while (child[p][ch] == 0) {
child[p][ch] = np;
p = fail[p];
}
if (child[p][ch] == np) fail[np] = root;
else {
int q = child[p][ch];
if (depth[q] == depth[p] + 1) fail[np] = q;
else {
int nq = newnode(depth[p] + 1);
fail[nq] = fail[q];
fail[q] = fail[np] = nq;
memcpy(child[nq], child[q], sizeof(child[q]));
while (child[p][ch] == q) {
child[p][ch] = nq;
p = fail[p];
}
}
}
cnt[last = np]++;
}
void init(char *s) {
size = 0;
root = last = newnode(0);
int len = strlen(s + 1);
for (int i = 1; i <= len; i++)
extend(s[i] - 'a');
}
long long f(long long x) {return x * (x + 1) / 2; }
void work(int pos) {
for (unsigned i = 0; i < a[pos].size(); i++) {
work(a[pos][i]);
cnt[pos] += cnt[a[pos][i]];
}
ans += f(cnt[pos]) * (depth[pos] - depth[fail[pos]]);
}
void calc() {
for (int i = 1; i < size; i++)
a[fail[i]].push_back(i);
work(0);
writeln(ans);
}
}
char s[MAXN];
int main() {
scanf("%s", s + 1);
SuffixAutomaton::init(s);
SuffixAutomaton::calc();
return 0;
}