Submission #1122291

#	Time	Username	Problem	Language	Result	Execution time	Memory
1122291		Tymond	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	377 ms	604 KiB

Main

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define fi first
#define se second
#define vi vector<int>
#define vll vector<long long>
#define pii pair<int, int>
#define pll pair<long long, long long>
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
mt19937_64 rng64(chrono::high_resolution_clock::now().time_since_epoch().count());
inline int rand(int l,int r){return uniform_int_distribution<int>(l, r)(rng);}
inline ll rand(ll l,ll r){return uniform_int_distribution<ll>(l, r)(rng64);}
#ifdef DEBUG
auto&operator<<(auto&o,pair<auto,auto>p){return o<<"("<<p.first<<", "<<p.second<<")";}
auto operator<<(auto&o,auto x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<","+!i++<<e;return o<<"}";}
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(X)
#else
#define debug(...){}
#endif
 
struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }
 
    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

const int INF = 1e9;
int n, m;
vector<pii> a;

bool comp(pii& x, pii& y){
    if(x.se != y.se){
        return x.se < y.se;
    }
    return x.fi < y.fi;
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);

    cin >> n >> m;
    a.resize(n);
    for(int i = 0; i < n; i++){
        cin >> a[i].fi >> a[i].se;
        if(a[i].se == -1){
            a[i].se = INF;
        }
    }

    sort(all(a), comp);
    ld ans = (ld)INF;
    for(int k = 0; k <= m; k++){
        vector<ld> dp(m - k + 1, (ld)INF);
        dp[0] = 0;
        ld p, val;
        for(int i = 0; i < n; i++){
            for(int j = min(m - k, i + 1); j >= 0; j--){
                p = dp[j];
                if(j > 0){
                    val = (ld)dp[j - 1] + (ld)a[i].fi / (k + 1);
                }else{
                    val = (ld)INF;
                }

                if(i - j + 1 <= 0){
                    dp[j] = min(val, p);
                }else if(i - j + 1 > k){
                    dp[j] = min(val, p);
                }else{
                    dp[j] = min(val, (ld)p + (ld)a[i].se / (i - j + 1));
                }
            }
        }
        ans = min(ans, dp[m - k]);
    }

    cout << fixed << setprecision(9);
    cout << ans<< '\n';

    return 0;
}

• 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