#include<iostream>
#include<vector>
#include<iomanip>
#include<utility>
#include<algorithm>
#define ld long double
using namespace std;
vector<pair<ld,ld>> vec;
int n,k;
ld solve(int m){
vector<vector<ld>> dp(n+1,vector<ld>(k-m+1,1e9+7));
dp[1][1]=vec[1].second,dp[1][0]=(m>0?vec[1].first:0);
for(int i=2;i<=n;i++){
for(int j=0;j<=min(k-m,i);j++){
dp[i][j]=min(dp[i][j],dp[i-1][j]+(i-j>m?0:vec[i].first/float(i-j)));
if(j>0) dp[i][j]=min(dp[i][j],dp[i-1][j-1]+vec[i].second/float(m+1));
}
}
/*for(int i=1;i<=n;i++){
for(int j=0;j<=k-m;j++) if(m==2) cout<<dp[i][j]<<" ";
cout<<"\n";
}*/
return dp[n][k-m];
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
cin>>n>>k;
vec.resize(n+1);
for(int i=1;i<=n;i++) cin>>vec[i].second>>vec[i].first;
for(int i=1;i<=n;i++) if(vec[i].first==-1) vec[i].first=1e9;
sort(next(vec.begin()),vec.end());
int l=0,r=k;
ld ans=1e9+7;
while(l<r){
int mid=(l+r)>>1;
ld a=solve(max(mid,0)),b=solve(min(mid+1,r));
ans=min(ans,min(a,b));
if(a>b) l=min(mid+1,r);
else r=(max(mid,0));
}
cout<<fixed<<setprecision(12)<<ans;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
324 KB |
Output is correct |
2 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 11 |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
324 KB |
Output is correct |
2 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 11 |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
28 ms |
2272 KB |
Output is correct |
2 |
Correct |
37 ms |
2320 KB |
Output is correct |
3 |
Correct |
25 ms |
2300 KB |
Output is correct |
4 |
Correct |
19 ms |
2344 KB |
Output is correct |
5 |
Correct |
14 ms |
2320 KB |
Output is correct |
6 |
Correct |
47 ms |
3256 KB |
Output is correct |
7 |
Correct |
12 ms |
2320 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
324 KB |
Output is correct |
2 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 11 |
3 |
Halted |
0 ms |
0 KB |
- |