結果

問題 No.2858 Make a Palindrome
ユーザー 👑 binapbinap
提出日時 2024-08-25 16:41:51
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 1,110 ms / 3,000 ms
コード長 3,496 bytes
コンパイル時間 4,812 ms
コンパイル使用メモリ 264,384 KB
実行使用メモリ 60,956 KB
最終ジャッジ日時 2024-08-25 16:42:11
合計ジャッジ時間 19,593 ms
ジャッジサーバーID
(参考情報)
judge2 / judge1
このコードへのチャレンジ
(要ログイン)

テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 1,110 ms
6,816 KB
testcase_01 AC 430 ms
6,944 KB
testcase_02 AC 414 ms
6,940 KB
testcase_03 AC 417 ms
6,940 KB
testcase_04 AC 448 ms
6,940 KB
testcase_05 AC 363 ms
6,944 KB
testcase_06 AC 174 ms
6,944 KB
testcase_07 AC 176 ms
6,940 KB
testcase_08 AC 172 ms
6,944 KB
testcase_09 AC 176 ms
6,944 KB
testcase_10 AC 313 ms
6,944 KB
testcase_11 AC 313 ms
6,940 KB
testcase_12 AC 316 ms
6,940 KB
testcase_13 AC 340 ms
6,940 KB
testcase_14 AC 313 ms
6,940 KB
testcase_15 AC 198 ms
6,944 KB
testcase_16 AC 206 ms
6,940 KB
testcase_17 AC 205 ms
6,940 KB
testcase_18 AC 220 ms
6,944 KB
testcase_19 AC 197 ms
6,940 KB
testcase_20 AC 252 ms
39,024 KB
testcase_21 AC 262 ms
40,056 KB
testcase_22 AC 142 ms
29,016 KB
testcase_23 AC 275 ms
39,388 KB
testcase_24 AC 243 ms
37,892 KB
testcase_25 AC 206 ms
36,076 KB
testcase_26 AC 200 ms
34,584 KB
testcase_27 AC 281 ms
58,904 KB
testcase_28 AC 224 ms
36,048 KB
testcase_29 AC 299 ms
40,076 KB
testcase_30 AC 290 ms
59,088 KB
testcase_31 AC 292 ms
59,072 KB
testcase_32 AC 290 ms
59,680 KB
testcase_33 AC 299 ms
58,856 KB
testcase_34 AC 287 ms
59,492 KB
testcase_35 AC 294 ms
59,304 KB
testcase_36 AC 296 ms
60,596 KB
testcase_37 AC 300 ms
59,660 KB
testcase_38 AC 294 ms
60,956 KB
testcase_39 AC 288 ms
59,472 KB
権限があれば一括ダウンロードができます

ソースコード

diff #

#include<bits/stdc++.h>
#include<atcoder/all>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
using namespace atcoder;
typedef long long ll;
typedef vector<int> vi;
typedef vector<long long> vl;
typedef vector<vector<int>> vvi;
typedef vector<vector<long long>> vvl;
typedef long double ld;
typedef pair<int, int> P;

ostream& operator<<(ostream& os, const modint& a) {os << a.val(); return os;}
template <int m> ostream& operator<<(ostream& os, const static_modint<m>& a) {os << a.val(); return os;}
template <int m> ostream& operator<<(ostream& os, const dynamic_modint<m>& a) {os << a.val(); return os;}
template<typename T> istream& operator>>(istream& is, vector<T>& v){int n = v.size(); assert(n > 0); rep(i, n) is >> v[i]; return is;}
template<typename U, typename T> ostream& operator<<(ostream& os, const pair<U, T>& p){os << p.first << ' ' << p.second; return os;}
template<typename T> ostream& operator<<(ostream& os, const vector<T>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : " "); return os;}
template<typename T> ostream& operator<<(ostream& os, const vector<vector<T>>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : ""); return os;}
template<typename T> ostream& operator<<(ostream& os, const set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;}
template<typename T> ostream& operator<<(ostream& os, const unordered_set<T>& se){for(T x : se) os << x << " "; os << "\n"; return os;}
template<typename S, auto op, auto e> ostream& operator<<(ostream& os, const atcoder::segtree<S, op, e>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;}
template<typename S, auto op, auto e, typename F, auto mapping, auto composition, auto id> ostream& operator<<(ostream& os, const atcoder::lazy_segtree<S, op, e, F, mapping, composition, id>& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;}

template<typename T> void chmin(T& a, T b){a = min(a, b);}
template<typename T> void chmax(T& a, T b){a = max(a, b);}

// thanks for snuke-san's blog
// https://snuke.hatenablog.com/entry/2014/12/02/235837
vector<int> manacher(vector<int>& s){
	int n = s.size();
	vector<int> res(n);
	int i = 0, j = 0;
	while(i < n){
		while(i - j >= 0 && i + j < n && s[i-j] == s[i+j]) ++j;
		res[i] = j;
		int k = 1;
		while(i - k >= 0 && k + res[i-k] < j) res[i+k] = res[i-k], ++k;
		i += k; j -= k;
	}
	return res;
}

vector<int> manacher(string& s){
	vector<int> s_int;
	for(char c : s) s_int.push_back(c);
	return manacher(s_int);
}

int solve(){
	int n;
	long long m;
	cin >> n >> m;
	string s;
	cin >> s;
	vector<int> history = {0};
	for(int time = 1; time <= 10; time++){
		string t;
		rep(_, time){
			rep(i, n){
				t += s[i];
				t += '_';
			}
		}
		auto vec = manacher(t);
		int x = 0;
		rep(i, n * time){
			chmax(x, 1 + (vec[2 * i] - 1) / 2 * 2);
		}
		rep(i, n * time){
			chmax(x, vec[2 * i + 1] / 2 * 2);
		}
		history.push_back(x);
		if(x >= m){
			cout << time << ' ' << "\n";
			return 0;
		}
	}
	if(history[3] == history[4]){
		cout << "-1\n";
		return 0;
	}
	long long ok = 5 * m, ng = 5;
	while(ok - ng > 1){
		long long mid = (ok + ng) / 2;
		long long x = history[3];
		long long diff = mid - 3;
		x += diff * (history[4] - history[3]);
		if(x >= m) ok = mid;
		else ng = mid;
	}
	cout << ok << "\n";
	return 0;
}

int main(){
	int t;
	cin >> t;
	rep(_, t) solve();
	
	return 0;
}
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