#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define all(aaa) aaa.begin(), aaa.end()
const int MOD[2] = { (int)1e9 + 7, (int)1e9 + 9 }, X[2] = { 997, 1009 },
N = 505, M = N * N;
ll p[2][M];
struct Hash {
int len;
pair<ll, ll> val, p;
Hash() {
len = 0;
val = { 0, 0 };
p = { 1, 1 };
}
Hash(char c) {
len = 1;
val = { c, c };
p = { X[0], X[1] };
}
bool operator < (const Hash &oth) const {
return val < oth.val;
}
};
Hash operator + (Hash a, Hash b) {
Hash c;
c.len = a.len + b.len;
c.val.first = (a.val.first * b.p.first + b.val.first) % MOD[0];
c.val.second = (a.val.second * b.p.second + b.val.second) % MOD[1];
c.p.first = a.p.first * b.p.first % MOD[0];
c.p.second = a.p.second * b.p.second % MOD[1];
return c;
}
Hash operator - (Hash a, Hash b) {
Hash c;
c.len = a.len - b.len;
c.val.first = (a.val.first - b.val.first * p[0][c.len] % MOD[0] + MOD[0]) % MOD[0];
c.val.second = (a.val.second - b.val.second * p[1][c.len] % MOD[1] + MOD[1]) % MOD[1];
c.p = { p[0][c.len], p[1][c.len] };
return c;
}
char s[N][N], t[N][N];
bool used[N][N];
Hash pref[M];
int n, m, k;
map<Hash, int> mp;
Hash bp(Hash h, int p) {
Hash r;
while (p > 0) {
if (p & 1)
r = r + h;
h = h + h;
p >>= 1;
}
return r;
}
void handle(string w) {
int len = w.size();
for (int i = 0; i < len; i++) {
pref[i + 1] = pref[i] + Hash(w[i]);
}
Hash mid, beg;
int last = -1;
for (int i = len - 1; i >= 0; i--) {
beg = Hash(w[i]) + beg;
if (len >= k + i) {
mp[pref[i + k] - pref[i]]++;
}
else {
int whole = k - (len - i),
rest = whole % len;
whole /= len;
if (last != whole) {
last = whole;
mid = bp(pref[len], whole);
}
mp[beg + mid + pref[rest]]++;
}
}
}
void solve(int n, int m, char a[N][N]) {
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
used[i][j] = 0;
}
}
for (int i = 0; i < n; i++) {
string w;
for (int j = 0; j < m; j++) {
if (!used[i][j]) {
w.clear();
int x = i, y = j;
while (!used[x][y]) {
used[x][y] = 1;
w.push_back(a[x][y]);
x = (x + n - 1) % n;
y = (y + 1) % m;
}
handle(w);
reverse(all(w));
handle(w);
}
}
w = a[i];
handle(w);
reverse(all(w));
handle(w);
}
}
ll gcd(ll a, ll b) {
return a ? gcd(b % a, a) : b;
}
signed main() {
#ifdef HOME
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
ios_base::sync_with_stdio(0);
cin.tie(0);
for (int i = 0; i < 2; i++) {
p[i][0] = 1;
for (int j = 1; j < M; j++) {
p[i][j] = p[i][j - 1] * X[i] % MOD[i];
}
}
cin >> n >> m >> k;
for (int i = 0; i < n; i++) {
cin >> s[i];
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
t[j][n - i - 1] = s[i][j];
}
}
solve(n, m, s);
solve(m, n, t);
ll p = 0, q = (ll)n * m * n * m * 64;
for (auto &x : mp) {
p += x.second * (ll)x.second;
}
ll g = gcd(p, q);
p /= g;
q /= g;
cout << p << "/" << q;
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
16 ms |
14456 KB |
Output is correct |
2 |
Correct |
16 ms |
14328 KB |
Output is correct |
3 |
Correct |
16 ms |
14456 KB |
Output is correct |
4 |
Correct |
16 ms |
14456 KB |
Output is correct |
5 |
Correct |
18 ms |
14584 KB |
Output is correct |
6 |
Correct |
44 ms |
18680 KB |
Output is correct |
7 |
Correct |
403 ms |
43284 KB |
Output is correct |
8 |
Correct |
1165 ms |
64240 KB |
Output is correct |