Submission #836556

#	Time	Username	Problem	Language	Result	Execution time	Memory
836556		green_gold_dog	JJOOII 2 (JOI20_ho_t2)	C++17	100 / 100	47 ms	5692 KiB

ho_t2

//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,sse,sse2,sse3,ssse3,sse4,abm,popcnt,mmx")
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef double db;
typedef long double ldb;
typedef complex<double> cd;

constexpr ll INF64 = 9'000'000'000'000'000'000, INF32 = 2'000'000'000, MOD = 1'000'000'007;
constexpr db PI = acos(-1);
constexpr bool IS_FILE = false, IS_TEST_CASES = false;

random_device rd;
mt19937 rnd32(rd());
mt19937_64 rnd64(rd());

template<typename T>
bool assign_max(T& a, T b) {
        if (b > a) {
                a = b;
                return true;
        }
        return false;
}

template<typename T>
bool assign_min(T& a, T b) {
        if (b < a) {
                a = b;
                return true;
        }
        return false;
}

template<typename T>
T square(T a) {
        return a * a;
}

template<>
struct std::hash<pair<ll, ll>> {
        ll operator() (pair<ll, ll> p) const {
                return ((__int128)p.first * MOD + p.second) % INF64;
        }
};

void solve() {
        ll n, k;
        cin >> n >> k;
        string s;
        cin >> s;
        vector<ll> pj(1, 0), po(1, 0), pi(1, 0);
        for (auto i : s) {
                pj.push_back(pj.back() + (i == 'J'));
                po.push_back(po.back() + (i == 'O'));
                pi.push_back(pi.back() + (i == 'I'));
        }
        ll ans = INF32;
        for (ll i = 0; i < n; i++) {
                ll now = i;
                if (pj.back() - pj[now] < k) {
                        break;
                }
                ll l = now, r = n;
                while (r - l > 1) {
                        ll mid = (l + r) / 2;
                        if (pj[mid] - pj[now] >= k) {
                                r = mid;
                        } else {
                                l = mid;
                        }
                }
                now = r;
                if (po.back() - po[now] < k) {
                        break;
                }
                l = now;
                r = n;
                while (r - l > 1) {
                        ll mid = (l + r) / 2;
                        if (po[mid] - po[now] >= k) {
                                r = mid;
                        } else {
                                l = mid;
                        }
                }
                now = r;
                if (pi.back() - pi[now] < k) {
                        break;
                }
                l = now;
                r = n;
                while (r - l > 1) {
                        ll mid = (l + r) / 2;
                        if (pi[mid] - pi[now] >= k) {
                                r = mid;
                        } else {
                                l = mid;
                        }
                }
                now = r;
                assign_min(ans, now - i - k * 3);
        }
        cout << (ans == INF32 ? -1 : ans) << '\n';
}

int main() {
        if (IS_FILE) {
                freopen("", "r", stdin);
                freopen("", "w", stdout);
        }
        ios_base::sync_with_stdio(false);
        cin.tie(0);
        cout.tie(0);
        ll t = 1;
        if (IS_TEST_CASES) {
                cin >> t;
        }
        for (ll i = 0; i < t; i++) {
                solve();
        }
}

Compilation message (stderr)

ho_t2.cpp: In function 'int main()':
ho_t2.cpp:112:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  112 |                 freopen("", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~
ho_t2.cpp:113:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  113 |                 freopen("", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 12 / 12
• Subtask 3: 87 / 87