Submission #619587

#	Time	Username	Problem	Language	Result	Execution time	Memory
619587		StrawHatWess	Let's Win the Election (JOI22_ho_t3)	C++17	100 / 100	1459 ms	4416 KiB

Main

//Never stop trying
#include "bits/stdc++.h"
using namespace std;
#define boost ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)

typedef long long ll;
typedef string str;
typedef long double ld;
typedef pair<int, int> pi;
#define fi first
#define se second
typedef vector<int> vi;
typedef vector<pi> vpi;
#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define endl "\n"
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)

const int MOD = 1e9 + 7; //998244353
const ll INF = 1e18;
const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0}; //right left down up

template<class T> using V = vector<T>;
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }
ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); } // divide a by b rounded up
//constexpr int log2(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
//mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());
ll random(ll a, ll b){
    return a + rng() % (b - a + 1);
}
#ifndef LOCAL  
#define cerr if(false) cerr
#endif
#define dbg(x) cerr << #x << " : " << x << endl; 
#define dbgs(x,y) cerr << #x << " : " << x << " / " << #y << " : " << y << endl;
#define dbgv(v) cerr << #v << " : " << "[ "; for(auto it : v) cerr << it << ' '; cerr << ']' << endl;
#define here() cerr << "here" << endl;

void IO() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin); 
    freopen("output.txt", "w", stdout);
#endif
}
/////////////////////////ONLY CLEAN CODES ALLOWED/////////////////////////

const int MX=510;

int N,K; 
vi a(MX),b(MX),p; 

vector<vector<ld>>memo; 
int nbCollTarget; 
ld solve(int i, int nbCollCur){
	ld &ind=memo[i][nbCollCur]; 
	if(ind!=-1) return ind; 

	int nbNormalCur=i-nbCollCur; 
	if(nbCollCur==nbCollTarget){
		int r = K - nbCollTarget - nbNormalCur; 

		vi vec; 
		FOR(j,i,N) vec.pb(a[p[j]]); 
		sort(all(vec)); 

		//dbgv(vec)

		ld ans=0; 
		FOR(j,0,r){
			int x=vec[j];
			ans+=((ld)(x))/(nbCollTarget+1); 
		}  
		return ans; 
	}

	ld ans=solve(i+1,nbCollCur+1) + ((ld)(b[p[i]]))/(nbCollCur+1); 

	if(nbNormalCur+nbCollTarget<K){
		ckmin(ans,solve(i+1,nbCollCur) + ((ld)(a[p[i]]))/(nbCollTarget+1) ); 
	}

	return ind=ans; 
}

int main() {
    boost; IO();

    cin>>N>>K; 

    FOR(i,0,N){
    	cin>>a[i]>>b[i]; 
    	p.pb(i); 
    	if(b[i]==-1) b[i]=1e9; 
    }

    sort(all(p), [&](int i, int j){
    	return b[i] < b[j]; 
    }); 

    //dbgv(p)

    ld ans=1e9; 
    FOR(n,0,K+1){
    	if(n && b[p[n-1]]==1e9) break; 

    	//nb collab wanted
    	nbCollTarget=n; 

    	memo.resize(N+5); 
    	FOR(i,0,N+5) memo[i].assign(N+5,-1); 

    	ckmin(ans,solve(0,0)); 
    }

    cout << fixed << setprecision(10) << ans << endl;
    
    

    return 0;
}
//Change your approach 

• 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