Submission #1290133

#	Time	Username	Problem	Language	Result	Execution time	Memory
1290133		Minbaev	Sure Bet (CEOI17_sure)	C++20	0 / 100	0 ms	332 KiB

sure

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>

//#pragma GCC target("avx,avx2,fma")
//#pragma GCC optimize("Ofast,unroll-loops")

using namespace std;
using namespace __gnu_pbds;

#define pb      push_back
#define all(x)  x.begin(),x.end()
#define int     long long
// #define double  long double
#define ar      array
#define mrand(a, b)   uniform_int_distribution<int>(a, b)(rng)

template<class T>bool umax(T &a,T b){if(a<b){a=b;return true;}return false;}
template<class T>bool umin(T &a,T b){if(b<a){a=b;return true;}return false;}

template<class T> using ste = tree<T, null_type, less_equal<T>,
rb_tree_tag, tree_order_statistics_node_update>;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

int binpow(int a, int b, int m){
    if(b <= 0)return 1; 	
    if(b % 2 == 0){
        int c = binpow(a,b/2,m);
        return (c*c)%m;
    }
    return (binpow(a,b-1,m)*a)%m;
}

int divi(int a, int b, int m){
    return (a*(binpow(b,m-2, m)))%m;
}

struct modint {
    static int mod;
    long long val;

    modint(long long v = 0) {
        val = v % mod;
        if (val < 0) val += mod;
    }

    modint& operator+=(const modint& other) {
        val += other.val;
        if (val >= mod) val -= mod;
        return *this;
    }
    modint& operator+=(long long other) {
        return *this += modint(other);
    }

    modint& operator-=(const modint& other) {
        val -= other.val;
        if (val < 0) val += mod;
        return *this;
    }
    modint& operator-=(long long other) {
        return *this -= modint(other);
    }

    modint& operator*=(const modint& other) {
        val = (val * other.val) % mod;
        return *this;
    }
    modint& operator*=(long long other) {
        return *this *= modint(other);
    }

    modint& operator/=(const modint& other) {
        val = divi(val, other.val, mod);
        return *this;
    }
    modint& operator/=(long long other) {
        return *this /= modint(other);
    }

    friend modint operator+(modint a, const modint& b) { return a += b; }
    friend modint operator+(modint a, long long b) { return a += b; }
    friend modint operator+(long long a, modint b) { return b += a; }

    friend modint operator-(modint a, const modint& b) { return a -= b; }
    friend modint operator-(modint a, long long b) { return a -= b; }
    friend modint operator-(long long a, modint b) { return modint(a) -= b; }

    friend modint operator*(modint a, const modint& b) { return a *= b; }
    friend modint operator*(modint a, long long b) { return a *= b; }
    friend modint operator*(long long a, modint b) { return b *= a; }

    friend modint operator/(modint a, const modint& b) { return a /= b; }
    friend modint operator/(modint a, long long b) { return a /= b; }
    friend modint operator/(long long a, modint b) { return modint(a) /= b; }

    friend ostream& operator<<(ostream& os, const modint& m) {
        return os << m.val;
    }
};

int modint::mod = 1e9 + 7;

namespace FAST {
    template<typename T>
    istream &operator>>(istream &cin, vector<T> &a) {
    for (T &i: a) cin >> i;
        return cin;
    }

    template<typename T>
    ostream &operator<<(ostream &cout, vector<T> &a) {
          for (T i: a) cout << i << ' ';
        return cout;
    }
}
using namespace FAST;

const int inf = 3e18 + 7;
const int mod = 1e9 + 7;
const int N = 6e5 + 5;
const int md = 998244353;

int rev(int a, int m){
	if (a == 1)return 1;
	return (1 - rev(m % a, a) * m) / a + m;
}

struct Bit {
    vector<int> b, b2;
    int n;

    Bit(int n) {
        this->n = n + 1;
        b.assign(n + 1, 0);
        b2.assign(n+1, 0);
    }

    void add(vector<int>&b, int idx, int x){
        while(idx <= n){
            b[idx] += x;
            idx += idx & -idx;
        }
    }

    void upd(int l, int r, int x){
        add(b, l, x);
        add(b, r+1, -x);
        add(b2, l, x*(l-1));
        add(b2, r+1, -x*r);
    }

    int sum(vector<int>&b, int idx){
        int res = 0;
        while(idx > 0){
            res += b[idx];
            idx -= idx & -idx;
        }
        return res;
    }

    int pref(int idx){
        return sum(b, idx) * idx - sum(b2, idx);
    }

    int get(int l, int r){                  
        return pref(r) - pref(l-1);
    }
};

int n,m,k;

void solve(){

	cin >> n;
	vector<long double>a(n), b(n);
	for(int i = 0;i<n;i++){
		cin >> a[i] >> b[i];
	}
	
	sort(all(a));
	sort(all(b));
	
	reverse(all(a));
	reverse(all(b));
	
	long double res = 0;
	vector<long double>pref(n + 1);
	for(int i = 1;i<=n;i++){
		pref[i] = pref[i-1] + b[i-1];
	}
	
	long double sum = 0;
	
	for(int i = 0;i<n;i++){
		sum += a[i];
		int l = 1, r = n;long double ans = -1;
		while(l <= r){
			int l1 = l + (r-l)/3;
			int r1 = r - (r-l)/3;
			
			long double ans3 = min((long double)sum - i - 1 - l1, (long double)pref[l1] - i - 1 - l1);
			long double ans2 = min((long double)sum - i - 1 - r1, (long double)pref[r1] - i - 1 - r1);
			
			if((long double)ans3 >= ans2){
				ans = ans3;
				r = r1 - 1;
			}
			else {
				ans = ans2;
				l = l1 + 1;
			}
		}
		
		if(ans == -1)continue;
		umax(res, ans);
	}
	
	cout << fixed << setprecision(6) << res << "\n";
	
	
}
/*
4
1.4 3.7
1.2 2
1.6 1.4
1.9 1.5
//---

10 2 5 4
7 2 3
4 8 3
9 10 1
6 7 3
9 2 3
10 1 2
8 2 2
5 2 1
3 8 2
8	
7
2 1
1 5
8 4
6 2
7 7
*/
 signed main()
{
//  freopen("seq.in", "r", stdin);
//  freopen("seq.out", "w", stdout);
    ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
    int tt=1;//cin >> tt;
    while(tt--)solve();	

}

• Subtask 1: 0 / 20
• Subtask 2: 0 / 40
• Subtask 3: 0 / 40