Submission #872467

#	Time	Username	Problem	Language	Result	Execution time	Memory
872467		sleepntsheep	Balloons (CEOI11_bal)	C++17	10 / 100	146 ms	5992 KiB

bal

#include <iostream>
#include <iomanip> 
#include <cmath>
#include <cstring>
#include <vector>
#include <algorithm>
#include <deque>
#include <set>
#include <utility>
#include <array>

using i64 = long long;
using u64 = unsigned long long;
using f64 = double;
using f80 = long double;

using namespace std;
#define ALL(x) x.begin(), x.end()
#define ShinLena cin.tie(nullptr)->sync_with_stdio(false);
#define N 200005

#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2,tune=native")

int n, x[N];
f80 r[N];

struct line
{
    f80 m, c;
    int i;
    f80 operator[](i64 x) { return m*x+c; }
    f80 intersectx(const line &l) { return f80(l.c - c) / (m - l.m); }
};


deque<line> lc;

void add(line k)
{
    while (lc.size())
    {
        if (lc.back().m >= k.m) lc.pop_back();
        else if (lc.size() > 1 && k.intersectx(lc.back()) <= k.intersectx(lc[lc.size()-2])) lc.pop_back();
        else break;
    }
    lc.push_back(k);
}

f80 qry(i64 x)
{
    u64 l = 1, r = lc.size(), z = 0;
    for (; l <= r;)
    {
        u64 m = (l+r)/2;
        if (lc[m].intersectx(lc[m-1]) <= x) z = m, l = m + 1;
        else r = m - 1;
    }
    return lc[z].i;
}

int main()
{
    ShinLena;
    cin >> n;
    for (int i = 0; i < n; ++i) cin >> x[i] >> r[i];

    add({-f80(*x)/r[0], 1L*f80(*x**x)/r[0], 0});

    for (int i = 1; i < n; ++i)
    {
        int j = qry(x[i]);
        f80 A = (1L * x[i] * x[i] + 1L * x[j] * x[j] - 2L * x[i] * x[j]) / (4L * r[j]);
        r[i] = min(r[i], A);

        add({-f80(x[i])/r[i], f80(x[i]*x[i]) / r[i], i});
    }

    cout << fixed << setprecision(3);
    for (int i = 0; i < n; ++i)
        cout << r[i] << '\n';

    return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10