結果

問題 No.2858 Make a Palindrome
ユーザー deuteridayo
提出日時 2024-08-25 16:19:15
言語 C++23
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 404 ms / 3,000 ms
コード長 6,278 bytes
コンパイル時間 5,578 ms
コンパイル使用メモリ 323,236 KB
実行使用メモリ 12,456 KB
最終ジャッジ日時 2024-08-25 16:19:24
合計ジャッジ時間 9,074 ms
ジャッジサーバーID
(参考情報)
judge3 / judge2
このコードへのチャレンジ
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ファイルパターン 結果
other AC * 40
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ソースコード

diff #
プレゼンテーションモードにする

#include<bits/stdc++.h>
#include<atcoder/all>
using namespace std;
using namespace atcoder;
using lint = long long;
using ulint = unsigned long long;
using llint = __int128_t;
struct edge;
using graph = vector<vector<edge>>;
#define endl '\n'
constexpr int INF = 1<<30;
constexpr lint INF64 = 1LL<<61;
constexpr lint mod107 = 1e9+7;
using mint107 = modint1000000007;
constexpr long mod = 998244353;
using mint = modint998244353;
lint ceilDiv(lint x, lint y){if(x >= 0){return (x+y-1)/y;}else{return x/y;}}
lint floorDiv(lint x, lint y){if(x >= 0){return x/y;}else{return (x-y+1)/y;}}
lint Sqrt(lint x) {assert(x >= 0); lint ans = sqrt(x); while(ans*ans > x)ans--; while((ans+1)*(ans+1)<=x)ans++; return ans;}
lint gcd(lint a,lint b){if(a<b)swap(a,b);if(a%b==0)return b;else return gcd(b,a%b);}
lint lcm(lint a,lint b){return (a / gcd(a,b)) * b;}
double Dist(double x1, double y1, double x2, double y2){return sqrt(pow(x1-x2, 2) + pow(y1-y2,2));}
lint DistSqr(lint x1, lint y1, lint x2, lint y2){return (x1-x2)*(x1-x2) + (y1-y2)*(y1-y2); }
string toString(lint n){string ans = "";if(n == 0){ans += "0";}else{while(n > 0){int a = n%10;char b = '0' + a;string c = "";c += b;n /= 10;ans = c +
    ans;}}return ans;}
string toString(lint n, lint k){string ans = toString(n);string tmp = "";while(ans.length() + tmp.length() < k){tmp += "0";}return tmp + ans;}
vector<lint>prime;void makePrime(lint n){prime.push_back(2);for(lint i=3;i<=n;i+=2){bool chk = true;for(lint j=0;j<prime.size() && prime[j]*prime[j]
    <= i;j++){if(i % prime[j]==0){chk=false;break;}}if(chk)prime.push_back(i);}}
lint Kai[20000001]; bool firstCallnCr = true;
lint ncrmodp(lint n,lint r,lint p){ if(firstCallnCr){ Kai[0] = 1; for(int i=1;i<=20000000;i++){ Kai[i] = Kai[i-1] * i; Kai[i] %= p;} firstCallnCr =
    false;} if(n<0)return 0;
if(n < r)return 0;if(n==0)return 1;lint ans = Kai[n];lint tmp = (Kai[r] * Kai[n-r]) % p;for(lint i=1;i<=p-2;i*=2){if(i & p-2){ans *= tmp;ans %= p
    ;}tmp *= tmp;tmp %= p;}return ans;}
#define rep(i, n) for(int i = 0; i < n; i++)
#define repp(i, x, y) for(int i = x; i < y; i++)
#define vec vector
#define pb push_back
#define eb emplace_back
#define se second
#define fi first
#define al(x) x.begin(),x.end()
#define ral(x) x.rbegin(),x.rend()
unsigned long Rand() {
static random_device seed;
static mt19937_64 engine(seed());
return engine();
}
struct Point {
lint x, y; int quad;
Point(lint X, lint Y) {
x = X;
y = Y;
quad = getQuad();
}
int getQuad() {
if(x >= 0) {
if(y >= 0) return 1;
else return 4;
} else {
if(y >= 0) return 2;
else return 3;
}
}
};
bool operator<(const Point &left, const Point &right) {
if(left.quad == right.quad) {
return left.y * right.x < left.x * right.y;
} else {
return left.quad < right.quad;
}
}
struct Frac {
lint upper, lower;
Frac() { Frac(0,1); }
Frac(lint u, lint l) {
assert(l != 0);
if(u <= 0 && l < 0) { upper = -u; lower = -l; }
else { upper = u; lower = l; }
reduction();
}
Frac(lint u) { upper = u; lower = 1; }
void reduction() {
if(upper != 0) {
lint g = gcd(abs(upper), abs(lower));
upper /= g; lower /= g;
if(lower < 0) {lower *= -1; upper *= -1; }
} else {
lower = 1;
}
}
Frac operator+(const Frac &other) {
lint L = lower * other.lower;
lint U = upper*other.lower + lower*other.upper;
return Frac(U, L);
}
Frac operator-(const Frac &other) {
lint L = lower * other.lower;
lint U = upper*other.lower - lower*other.upper;
upper = U; lower = L;
return Frac(U, L);
}
bool operator<=(const Frac &other) {
return upper*other.lower <= lower*other.upper;
}
Frac operator*(const Frac &other) {
lint L = lower * other.lower;
lint U = upper * other.upper;
return Frac(U, L);
}
Frac operator/(const Frac &other) {
assert(other.upper != 0);
lint L = lower * other.upper;
lint U = upper * other.lower;
return Frac(U, L);
}
};
bool operator<(const Frac &left, const Frac &right) {
llint L = left.upper;
L *= right.lower;
llint R = right.upper;
R *= left.lower;
return L < R;
}
lint extGCD(lint a, lint b, lint &x, lint &y) {
if (b == 0) {
x = 1; y = 0;
return a;
}
lint d = extGCD(b, a%b, y, x);
y -= a/b * x;
return d;
}
struct edge{
edge(lint v, lint c = 1) {to = v, cost = c;}
lint to;
lint cost;
};
vector<lint>dijkstra(int s, graph &g) {
vec<lint>ret(g.size(), INF64);
priority_queue<pair<lint, lint>>que;
que.push({-0, s});
ret[s] = 0;
while(!que.empty()) {
auto q = que.top();
que.pop();
for(auto&& e: g[q.second]) {
if(ret[e.to] > -q.first + e.cost) {
ret[e.to] = -q.first + e.cost;
que.push({-ret[e.to], e.to});
}
}
}
return ret;
}
vec<lint> manacher(string S)
{
vec<lint>R(S.size());
int i = 0, j = 0;
while (i < S.size()) {
while (i-j >= 0 && i+j < S.size() && S[i-j] == S[i+j]) ++j;
R[i] = j;
int k = 1;
while (i-k >= 0 && k+R[i-k] < j) R[i+k] = R[i-k], ++k;
i += k; j -= k;
}
rep(i, S.size()) {
if(i%2 == R[i]%2) R[i]--;
}
return R;
}
lint f(string s) {
string t;
for(auto c: s) {
t += c;
t += "#";
}
t.pop_back();
auto b = manacher(t);
lint ans = 0;
rep(i, b.size()) {
ans = max(ans, b[i]);
}
return ans;
}
void solve() {
lint n, m;
cin >> n >> m;
string s;
cin >> s;
lint sf = f(s);
string t = s+s;
lint ssf = f(t);
if(sf >= m) {
cout << 1 << endl;
}
else if(sf == n) {
cout << (m + n - 1) / n << endl;
} else if(ssf >= m) {
cout << 2 << endl;
} else if(ssf >= n){
lint ret = ssf%n;
cout << (m - ret + n - 1) / n + 1 << endl;
} else {
cout << -1 << endl;
}
}
int main(){
int t;
cin >> t;
rep(tt, t)solve();
}
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