結果
| 問題 |
No.1695 Mirror Mirror
|
| コンテスト | |
| ユーザー |
 tokusakurai
|
| 提出日時 | 2021-10-01 22:22:00 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 60 ms / 2,000 ms |
| コード長 | 6,240 bytes |
| コンパイル時間 | 2,445 ms |
| コンパイル使用メモリ | 202,136 KB |
| 最終ジャッジ日時 | 2025-01-24 19:12:29 |
|
ジャッジサーバーID （参考情報） |
judge1 / judge5 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 4 |
| other | AC * 61 |
ソースコード
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < n; i++)
#define rep2(i, x, n) for (int i = x; i <= n; i++)
#define rep3(i, x, n) for (int i = x; i >= n; i--)
#define each(e, v) for (auto &e : v)
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) (int)x.size()
using ll = long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
template <typename T>
bool chmax(T &x, const T &y) {
return (x < y) ? (x = y, true) : false;
}
template <typename T>
bool chmin(T &x, const T &y) {
return (x > y) ? (x = y, true) : false;
}
template <typename T>
int flg(T x, int i) {
return (x >> i) & 1;
}
template <typename T>
void print(const vector<T> &v, T x = 0) {
int n = v.size();
for (int i = 0; i < n; i++) cout << v[i] + x << (i == n - 1 ? '\n' : ' ');
}
template <typename T>
void printn(const vector<T> &v, T x = 0) {
int n = v.size();
for (int i = 0; i < n; i++) cout << v[i] + x << '\n';
}
template <typename T>
int lb(const vector<T> &v, T x) {
return lower_bound(begin(v), end(v), x) - begin(v);
}
template <typename T>
int ub(const vector<T> &v, T x) {
return upper_bound(begin(v), end(v), x) - begin(v);
}
template <typename T>
void rearrange(vector<T> &v) {
sort(begin(v), end(v));
v.erase(unique(begin(v), end(v)), end(v));
}
template <typename T>
vector<int> id_sort(const vector<T> &v, bool greater = false) {
int n = v.size();
vector<int> ret(n);
iota(begin(ret), end(ret), 0);
sort(begin(ret), end(ret), [&](int i, int j) { return greater ? v[i] > v[j] : v[i] < v[j]; });
return ret;
}
struct io_setup {
io_setup() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout << fixed << setprecision(15);
}
} io_setup;
const int inf = (1 << 30) - 1;
const ll INF = (1LL << 60) - 1;
const int MOD = 1000000007;
// const int MOD = 998244353;
template <typename Monoid>
struct Segment_Tree {
using F = function<Monoid(Monoid, Monoid)>;
int n;
vector<Monoid> seg;
const F f;
const Monoid e1;
// f(f(a,b),c) = f(a,f(b,c)), f(e1,a) = f(a,e1) = a
Segment_Tree(const vector<Monoid> &v, const F &f, const Monoid &e1) : f(f), e1(e1) {
int m = v.size();
n = 1;
while (n < m) n <<= 1;
seg.assign(2 * n, e1);
copy(begin(v), end(v), seg.begin() + n);
for (int i = n - 1; i > 0; i--) seg[i] = f(seg[2 * i], seg[2 * i + 1]);
}
Segment_Tree(int m, const Monoid &x, const F &f, const Monoid &e1) : f(f), e1(e1) {
n = 1;
while (n < m) n <<= 1;
seg.assign(2 * n, e1);
vector<Monoid> v(m, x);
copy(begin(v), end(v), begin(seg) + n);
for (int i = n - 1; i > 0; i--) seg[i] = f(seg[2 * i], seg[2 * i + 1]);
}
void change(int i, const Monoid &x, bool update = true) {
if (update) {
seg[i + n] = x;
} else {
seg[i + n] = f(seg[i + n], x);
}
i += n;
while (i >>= 1) { seg[i] = f(seg[2 * i], seg[2 * i + 1]); }
}
Monoid query(int l, int r) const {
Monoid L = e1, R = e1;
l += n, r += n;
while (l < r) {
if (l & 1) L = f(L, seg[l++]);
if (r & 1) R = f(seg[--r], R);
l >>= 1, r >>= 1;
}
return f(L, R);
}
Monoid operator[](int i) const { return seg[n + i]; }
template <typename C>
int find_subtree(int i, const C &check, const Monoid &x, Monoid &M, bool type) const {
while (i < n) {
Monoid nxt = type ? f(seg[2 * i + type], M) : f(M, seg[2 * i + type]);
if (check(nxt, x)) {
i = 2 * i + type;
} else {
M = nxt, i = 2 * i + (type ^ 1);
}
}
return i - n;
}
template <typename C>
int find_first(int l, const C &check, const Monoid &x) const { // check((区間[l,r]での演算結果), x)を満たす最小のr
Monoid L = e1;
int a = l + n, b = n + n;
while (a < b) {
if (a & 1) {
Monoid nxt = f(L, seg[a]);
if (check(nxt, x)) return find_subtree(a, check, x, L, false);
L = nxt, a++;
}
a >>= 1, b >>= 1;
}
return n;
}
template <typename C>
int find_last(int r, const C &check, const Monoid &x) const { // check((区間[l,r)での演算結果), x)を満たす最大のl
Monoid R = e1;
int a = n, b = r + n;
while (a < b) {
if (b & 1 || a == 1) {
Monoid nxt = f(seg[--b], R);
if (check(nxt, x)) return find_subtree(b, check, x, R, true);
R = nxt;
}
a >>= 1, b >>= 1;
}
return -1;
}
};
template <typename T>
vector<int> manachar(const T &s) {
int n = s.size();
vector<int> ret(n);
int i = 0, j = 0;
while (i < n) {
while (i - j >= 0 && i + j < n && s[i - j] == s[i + j]) j++;
ret[i] = j;
int k = 1;
while (i - k >= 0 && k + ret[i - k] < j) ret[i + k] = ret[i - k], k++;
i += k, j -= k;
}
return ret;
}
int main() {
int N, M;
string S, T;
cin >> N >> M >> S >> T;
string X = T;
reverse(all(X));
if (M & 1 || T != X) {
cout << "-1\n";
return 0;
}
M /= 2;
string U;
U += T[0];
rep2(i, 1, M - 1) {
U += '_';
U += T[i];
}
vector<int> c = manachar(U);
// print(c);
auto f = [](int a, int b) { return min(a, b); };
Segment_Tree<int> seg(M, inf, f, inf);
seg.change(M - 1, 1);
rep3(i, M - 2, 0) {
int x = seg.query(i + 1, i + c[2 * i + 1] / 2 + 1);
if (x != inf) seg.change(i, x + 1);
}
// rep(i, M) cout << seg[i] << ' ';
// cout << '\n';
int ans = inf;
rep(i, M) {
if (i == N || S[i] != T[i]) break;
chmin(ans, seg[i]);
}
rep(i, M) {
if (i == N || S[N - 1 - i] != T[i]) break;
chmin(ans, seg[i]);
}
cout << (ans == inf ? -1 : ans) << '\n';
}