Submission #865807

#	Time	Username	Problem	Language	Result	Execution time	Memory
865807		green_gold_dog	Seesaw (JOI22_seesaw)	C++17	1 / 100	75 ms	348 KiB

seesaw

//#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;
        cin >> n;
        deque<ll> arr(n);
        ll s = 0;
        for (ll i = 0; i < n; i++) {
                cin >> arr[i];
                s += arr[i];
        }
        double ans = INF32;
        for (ll i = 0; i < (1 << (n - 1)); i++) {
                deque<ll> d = arr;
                ll sum = s;
                double mi = sum / (double)n, ma = sum / (double)n;
                for (ll j = 0; j < n - 1; j++) {
                        if ((i >> j) & 1) {
                                sum -= d.front();
                                d.pop_front();
                        } else {
                                sum -= d.back();
                                d.pop_back();
                        }
                        assign_min(mi, sum / (double)d.size());
                        assign_max(ma, sum / (double)d.size());
                }
                assign_min(ans, ma - mi);
        }
        cout << setprecision(20) << 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)

seesaw.cpp: In function 'int main()':
seesaw.cpp:82:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |                 freopen("", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~
seesaw.cpp:83:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |                 freopen("", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 0 / 33
• Subtask 3: 0 / 33
• Subtask 4: 0 / 33