結果

問題 No.2454 Former < Latter
ユーザー kaikeykaikey
提出日時 2023-09-01 21:57:37
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
WA  
実行時間 -
コード長 6,336 bytes
コンパイル時間 2,539 ms
コンパイル使用メモリ 208,552 KB
実行使用メモリ 8,416 KB
最終ジャッジ日時 2024-06-11 03:44:33
合計ジャッジ時間 5,479 ms
ジャッジサーバーID
(参考情報)
judge2 / judge5
このコードへのチャレンジ
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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 2 ms
5,248 KB
testcase_01 WA -
testcase_02 WA -
testcase_03 AC 63 ms
8,292 KB
testcase_04 WA -
testcase_05 WA -
testcase_06 WA -
testcase_07 WA -
testcase_08 WA -
testcase_09 WA -
testcase_10 WA -
testcase_11 AC 64 ms
8,284 KB
testcase_12 AC 65 ms
8,416 KB
testcase_13 WA -
testcase_14 WA -
testcase_15 WA -
testcase_16 WA -
testcase_17 AC 1,307 ms
5,376 KB
testcase_18 WA -
testcase_19 WA -
testcase_20 WA -
testcase_21 WA -
testcase_22 WA -
testcase_23 WA -
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 <random>
#include <chrono>
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define SZ(x) ((lint)(x).size())
#define FOR(i, begin, end) for(lint i=(begin),i##_end_=(end);i<i##_end_;++i)
#define IFOR(i, begin, end) for(lint i=(end)-1,i##_begin_=(begin);i>=i##_begin_;--i)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
#define endk '\n'
using namespace std; typedef unsigned long long _ulong; typedef long long int lint; typedef double ld; typedef pair<lint, lint> plint; typedef pair<ld, ld> pld;
struct fast_ios { fast_ios() { cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(30); }; } fast_ios_;
template<class T> auto add = [](T a, T b) -> T { return a + b; };
template<class T> auto mul = [](T a, T b) -> T { return a * b; };
template<class T> auto f_max = [](T a, T b) -> T { return max(a, b); };
template<class T> auto f_min = [](T a, T b) -> T { return min(a, b); };
template<class T> using V = vector<T>;
using Vl = V<lint>; using VVl = V<Vl>; using VVVl = V<V<Vl>>;
template< typename T > ostream& operator<<(ostream& os, const vector< T >& v) {
    for (int i = 0; i < (int)v.size(); i++) os << v[i] << (i + 1 != v.size() ? " " : "");
    return os;
}
template< typename T >istream& operator>>(istream& is, vector< T >& v) {
    for (T& in : v) is >> in;
    return is;
}
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
template <class T>
T div_floor(T a, T b) {
    if (b < 0) a *= -1, b *= -1;
    return a >= 0 ? a / b : (a + 1) / b - 1;
}
template <class T>
T div_ceil(T a, T b) {
    if (b < 0) a *= -1, b *= -1;
    return a > 0 ? (a - 1) / b + 1 : a / b;
}
template <class F> struct rec {
    F f;
    rec(F&& f_) : f(std::forward<F>(f_)) {}
    template <class... Args> auto operator()(Args &&... args) const {
        return f(*this, std::forward<Args>(args)...);
    }
};
lint gcd(lint a, lint b) { if (b == 0) return a; else return gcd(b, a % b); }
lint digit(lint a) { return (lint)log10(a); }
lint e_dist(plint a, plint b) { return abs(a.first - b.first) * abs(a.first - b.first) + abs(a.second - b.second) * abs(a.second - b.second); }
lint m_dist(plint a, plint b) { return abs(a.first - b.first) + abs(a.second - b.second); }
bool check_overflow(lint a, lint b, lint limit) { if (b == 0) return false; return a > limit / b; } // a * b > c => true
void Worshall_Floyd(VVl& g) { REP(k, SZ(g)) REP(i, SZ(g)) REP(j, SZ(g)) chmin(g[i][j], g[i][k] + g[k][j]); }
const lint MOD1000000007 = 1000000007, MOD998244353 = 998244353, INF = 1e18;
lint dx[8] = { 0, 1, 0, -1, 1, -1, 1, -1 }, dy[8] = { 1, 0, -1, 0, -1, -1, 1, 1 };
bool YN(bool flag) { cout << (flag ? "YES" : "NO") << endk; return flag; } bool yn(bool flag) { cout << (flag ? "Yes" : "No") << endk; return flag; }
struct Edge {
    lint from, to;
    lint cost;
    Edge() {

    }
    Edge(lint u, lint v, lint c) {
        cost = c;
        from = u;
        to = v;
    }
    bool operator<(const Edge& e) const {
        return cost < e.cost;
    }
};
struct WeightedEdge {
    lint to;
    lint cost;
    WeightedEdge(lint v, lint c) {
        to = v;
        cost = c;
    }
    bool operator<(const WeightedEdge& e) const {
        return cost < e.cost;
    }
};
using WeightedGraph = V<V<WeightedEdge>>;
typedef pair<plint, lint> tlint;
typedef pair<ld, ld> pld;
typedef pair<plint, plint> qlint;
typedef pair<Edge, lint> pEd;
typedef pair<lint, Vl> vVl;
typedef pair<set<lint>, set<lint>> pset;

struct RollingHash {
    const _ulong MASK30 = (1ULL << 30) - 1;
    const _ulong MASK31 = (1ULL << 31) - 1;
    const _ulong MOD = (1ULL << 61) - 1;
    const _ulong MASK61 = MOD;

    vector<_ulong> hashed, power;

    RollingHash(const string& s, _ulong base) {
        int sz = SZ(s);
        hashed.assign(sz + 1, 0);
        power.assign(sz + 1, 0);
        power[0] = 1;
        for (int i = 0; i < sz; i++) {
            power[i + 1] = mul(power[i], base);
            hashed[i + 1] = mul(hashed[i], base) + s[i];
            if (hashed[i + 1] >= MOD) hashed[i + 1] -= MOD;
        }
    }

    //乱数生成、main関数にコピペする
    void generate_base() {
        _ulong base;
        {
            //乱数生成
            random_device seed_gen;
            mt19937 engine(seed_gen());
            uniform_real_distribution<> dist1(129, INT_MAX);
            base = dist1(engine);
        }
    }

    _ulong get(int l, int r) const {
        _ulong ret = hashed[r] + MOD - mul(hashed[l], power[r - l]);
        if (ret >= MOD) ret -= MOD;
        return ret;
    }

    //a*b mod 2^61-1を返す関数
    inline _ulong mul(_ulong a, _ulong b) const {
        _ulong u_a = a >> 31;//aの31bit以降
        _ulong d_a = a & MASK31;//aの31bit未満
        _ulong u_b = b >> 31;
        _ulong d_b = b & MASK31;

        _ulong mid = d_a * u_b + u_a * d_b;
        _ulong u_mid = mid >> 30;
        _ulong d_mid = mid & MASK30;
        return CalcMod(u_a * u_b * 2 + u_mid + (d_mid << 31) + d_a * d_b);
    }

    //mod 2^61-1を返す関数
    inline _ulong CalcMod(_ulong x) const {
        _ulong u_x = x >> 61;
        _ulong d_x = x & MASK61;
        _ulong res = u_x + d_x;
        if (res >= MOD) res -= MOD;
        return res;
    }
};

int main() {
    lint T;
    cin >> T;
    while (T--) {
        lint N;
        cin >> N;
        string s;
        cin >> s;

        _ulong base;
        {
            //乱数生成
            random_device seed_gen;
            mt19937 engine(seed_gen());
            uniform_real_distribution<> dist1(129, INT_MAX);
            base = dist1(engine);
        }
        RollingHash rh(s, base);
        
        lint ans = 0;
        REP(i, N - 1) {
            lint ng = 0, ok = min(i + 1, N - (i + 1));
            while (ok - ng > 1) {
                lint mid = (ok + ng) / 2;
                if (rh.get(0, ok) != rh.get(i + 1, i + 1 + ok)) ok = mid;
                else ng = mid;
            }
            if (s[ng] == s[i + 1 + ng]) {
                if (i + 1 < N - (i + 1)) ans++;
            }
            else {
                if (s[ng] < s[i + 1 + ng]) ans++;
            }
        }
        cout << ans << endk;
    }
}
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