Submission #908079

#	Time	Username	Problem	Language	Result	Execution time	Memory
908079		gaga999	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	14 ms	604 KiB

Main

#include <cstdio>
#include <stdio.h>
#include <iostream>
#include <math.h>
#include <vector>
#include <queue>
#include <stack>
#include <deque>
#include <algorithm>
#include <utility>
#include <set>
#include <map>
#include <stdlib.h>
#include <cstring>
#include <string.h>
#include <string>
#include <sstream>
#include <assert.h>
#include <climits>
#include <sstream>
#include <numeric>
#include <time.h>
#include <limits.h>
#include <list>
#include <bitset>
#include <unordered_map>
#include <unordered_set>
#include <random>
#include <iomanip>
#include <complex>
#include <chrono>
#include <fstream>
#include <functional>
#include <unistd.h>
// #pragma GCC optimize("Ofast,no-stack-protector")
// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx,avx2,bmi,bmi2,lzcnt,popcnt")
#define lowbit(x) ((x) & -(x))
#define ml(a, b) ((1ll * (a) * (b)) % M)
#define tml(a, b) (a) = ((1ll * (a) * (b)) % M)
#define ad(a, b) ((0ll + (a) + (b)) % M)
#define tad(a, b) (a) = ((0ll + (a) + (b)) % M)
#define mi(a, b) ((0ll + M + (a) - (b)) % M)
#define tmi(a, b) (a) = ((0ll + M + (a) - (b)) % M)
#define tmin(a, b) (a) = min((a), (b))
#define tmax(a, b) (a) = max((a), (b))
#define iter(a) (a).begin(), (a).end()
#define riter(a) (a).rbegin(), (a).rend()
#define init(a, b) memset((a), (b), sizeof(a))
#define cpy(a, b) memcpy((a), (b), sizeof(a))
#define uni(a) a.resize(unique(iter(a)) - a.begin())
#define pb emplace_back
#define mpr make_pair
#define ls(i) ((i) << 1)
#define rs(i) ((i) << 1 | 1)
#define INF 0x3f3f3f3f
#define NIF 0xc0c0c0c0
#define eps 1e-9
#define F first
#define S second
#define AC cin.tie(0)->sync_with_stdio(0)
using namespace std;
typedef long long llt;
typedef pair<int, int> pii;
typedef pair<double, double> pdd;
typedef pair<llt, llt> pll;
typedef complex<double> cd;
// const int M = 998244353;

// random_device rm;
// mt19937 rg(rm());
// default_random_engine rg(rm());
// uniform_int_distribution<int> rd(INT_MIN, INT_MAX);
// uniform_real_distribution<double> rd(0, M_PI);

void db() { cerr << "\n"; }
template <class T, class... U>
void db(T a, U... b) { cerr << a << " ", db(b...); }

inline char gc()
{
    const static int SZ = 1 << 16;
    static char buf[SZ], *p1, *p2;
    if (p1 == p2 && (p2 = buf + fread(p1 = buf, 1, SZ, stdin), p1 == p2))
        return -1;
    return *p1++;
}
void rd() {}
template <typename T, typename... U>
void rd(T &x, U &...y)
{
    x = 0;
    bool f = 0;
    char c = gc();
    while (!isdigit(c))
        f ^= !(c ^ 45), c = gc();
    while (isdigit(c))
        x = (x << 1) + (x << 3) + (c ^ 48), c = gc();
    f && (x = -x), rd(y...);
}

template <typename T>
void prt(T x)
{
    if (x < 0)
        putchar('-'), x = -x;
    if (x > 9)
        prt(x / 10);
    putchar((x % 10) ^ 48);
}

const int N = 505;
pii ar[N];
int ps[N];
double dp[N];

signed main()
{
    int n, k;
    rd(n, k);
    for (int i = 0; i < n; i++)
    {
        rd(ar[i].S, ar[i].F);
        if (!~ar[i].F)
            ar[i].F = INF;
    }
    sort(ar, ar + n);
    {
        priority_queue<int, vector<int>, greater<int>> pq;
        for (int i = n - 1; i >= k; i--)
            pq.push(ar[i].S);
        for (int i = k - 1; i >= 0; i--)
            pq.push(ar[i].S), ps[i] = ps[i + 1] + pq.top(), pq.pop();
    }
    double ans = ps[0];
    auto slv = [&](int t) -> double
    {
        fill(dp, dp + t + 1, 1e12), dp[0] = 0;
        double res = 1e12;
        for (int i = 0; i < n; i++)
        {
            for (int j = t; j >= 0; j--)
            {
                dp[j] += ar[i].S / double(t + 1);
                if (j)
                    tmin(dp[j], dp[j - 1] + ar[i].F / double(j));
            }
            tmin(res, dp[t] + ps[i + 1] / double(t + 1));
        }
        return res;
    };
    int l = 1, r = k - 1;
    while (l < r - 2)
    {
        int m1 = (l * 2 + r) / 3, m2 = (l + r * 2) / 3;
        if (slv(m1) < slv(m2))
            r = m2;
        else
            l = m1;
    }
    for (int i = l; i <= r; i++)
        tmin(ans, slv(i));
    printf("%.10lf\n", ans);
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 11 / 11
• Subtask 4: 12 / 12
• Subtask 5: 33 / 33
• Subtask 6: 11 / 11
• Subtask 7: 23 / 23