This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include "bits/stdc++.h"
#pragma optimize ("Bismillahirrahmanirrahim")
using namespace std;
#define pb push_back
#define ff first
#define ss second
#define endl "\n"
#define int long long
#define double long double
#define sz(x) ((int)(x).size())
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define what_is(x) cerr << #x << " is " << x << endl;
//#define m (l+r)/2
constexpr int N=200005;
constexpr int MOD=1000000007;
constexpr int INF2 = LLONG_MAX;
constexpr int INF=(int)1e18;
constexpr int LOG=30;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tp;
typedef priority_queue<pii,vector<pii>,greater<pii>> min_pq;
typedef priority_queue<pii> max_pq;
typedef long long ll;
//to think//
/*
* graph approach
* dp
* dividing the problem to smaller statements
* finding the real constraint
* sqrt decomposition
* greedy approach
* pigeonhole principle
* rewriting the problem/equality
* bitwise approaches
* binary search if monotonic
* divide and conquer
* combinatorics
* inclusion - exclusion
* think like bfs
*/
inline int in()
{
int x;cin >> x;
return x;
}
inline string in2()
{
string x;cin >> x;
return x;
}
void solve()
{
int n=in(),k=in();
vector<array<double,2>> v(n);
for(int i=0;i<n;i++)
{
v[i][1]=in(),v[i][0]=in();
if(v[i][0]==-1) v[i][0]=INF*1.0;
}
sort(all(v));
double suf[n+1][n+1];
double ans=INF*1.0;
multiset<double> cur;
for(int i=n-1;i>=0;i--)
{
double pre=0;
cur.insert(v[i][1]);
int p=0;
suf[i][0]=pre;
for(int j:cur)
{
pre+=j;
suf[i][++p]=pre;
}
for(int j=p+1;j<=n;j++) suf[i][j]=INF*1.0;
}
ans=min(ans,(double)suf[0][k]);
for(int goal=1;goal<=k;goal++)
{
double dp[n+2][goal+2];
for(int j=0;j<=n;j++)
for(int i=0;i<=goal;i++)
dp[j][i]=INF*1.0;
dp[0][0]=0.0;
double bol=goal;
for(int i=1;i<=n;i++)
{
for(int j=0;j<=goal;j++)
{
dp[i][j]=min(dp[i-1][j]+v[i-1][1]/(bol+1.0),dp[i][j]);
if(j>0) dp[i][j]=min(dp[i][j],dp[i-1][j-1]+v[i-1][0]/(j*1.0));
if(j==goal && i+1<=n && i<=k) ans=min(ans, dp[i][j]+ suf[i+1][k-i]/(bol+1.0) );
//if(j==goal && i==n) ans=min(ans,dp[i][j]);
if(j==goal && i>=k) ans=min(ans,dp[i][j]);
}
}
}
cout << ans << endl;
}
int32_t main(){
cin.tie(0); ios::sync_with_stdio(0);
cout << fixed << setprecision(15);
int t=1;//cin>> t;
for(int i=1;i<=t;i++)
{
// cout << "Case #" << i << ": ";
solve();
}
return 0;
}
Compilation message (stderr)
Main.cpp:2: warning: ignoring '#pragma optimize ' [-Wunknown-pragmas]
2 | #pragma optimize ("Bismillahirrahmanirrahim")
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