Submission #678242

#	Time	Username	Problem	Language	Result	Execution time	Memory
678242		CodePlatina	Seesaw (JOI22_seesaw)	C++17	0 / 100	0 ms	212 KiB

seesaw

#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <tuple>
#include <iomanip>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define piii pair<int, pii>
#define plll pair<long long, pll>
#define tiii tuple<int, int, int>
#define tiiii tuple<int, int, int, int>
#define ff first
#define ss second
#define ee ss.ff
#define rr ss.ss
const int INF = (int)1e9 + 7;

using namespace std;

bool cmp(pll x, pll y)
{
    return (__int128)x.ff * y.ss < (__int128)y.ff * x.ss;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n; cin >> n;
    int A[n]; for(auto &i : A) cin >> i;
    long long ps[n + 1]{}; for(int i = 1; i <= n; ++i) ps[i] = ps[i - 1] + A[i - 1];

    pll t = {ps[n], n};
    pll s = t;
    int l = 0, r = n;
    while(l + 1 < r)
    {
        if(cmp(t, pll{ps[r] - ps[l + 1], r - l - 1})) --r;
        else ++l;
        if(cmp(pll{ps[r] - ps[l], r - l}, s)) s = pll{ps[r] - ps[l], r - l};
    }
    long double ans = (long double)t.ff / t.ss - (long double)s.ff / s.ss;

    s = t;
    l = 0, r = n;
    while(l + 1 < r)
    {
        if(cmp(pll{ps[r - 1] - ps[l], r - l - 1}, t)) ++l;
        else --r;
        if(cmp(s, pll{ps[r] - ps[l], r - l})) s = pll{ps[r] - ps[l], r - l};
    }
    ans = min(ans, (long double)s.ff / s.ss - (long double)t.ff / t.ss);

    cout << fixed << setprecision(20) << ans;
}

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